| HYDRO COMPANY LIMITED | Private company limited by shares | Dissolved |
| GEO HYDRO INC LIMITED | Private company limited by shares | Dissolved |
| HYDRO CUT LIMITED | Private company limited by shares | Dissolved |
| PAN PRD HYDRO LIMITED | Private company limited by shares | Dissolved |
| AIT HYDRO LIMITED | Private company limited by shares | Live |
| HYDRO LIMITED | Private company limited by shares | Dissolved |
| HYDRO LIMITED | Private company limited by shares | Live |
| HYDRO8 LIMITED | Private company limited by shares | Live |
| Hydrobio International Co., Limited | Private company limited by shares | Live |
| HYDROBIOTICS LIMITED | Private company limited by shares | Dissolved |
| HYDROBOND HONG KONG LIMITED | Private company limited by shares | Live |
| HYDROBRIGHT (HONGKONG) INDUSTRIAL CO., LIMITED | Private company limited by shares | Live |
| HYDROCARBONS (ASIA) LIMITED | Private company limited by shares | Live |
| FAR EASTERN HYDROCARBONS LIMITED | Private company limited by shares | Dissolved |
| JARCH SL HYDROCARBONS LIMITED | Private company limited by shares | Live |
| JARCH RSS HYDROCARBONS LIMITED | Private company limited by shares | Live |
| OREN HYDROCARBONS (QINGDAO) CO., LIMITED | Private company limited by shares | Live |
| Hydrocarbons Transportation and Storage Systems Limited | Private company limited by shares | Live |
| S.E.A. HYDROCARBONS TECHNOLOGIES LIMITED | Private company limited by shares | Dissolved |
| Hydrocation Limited | Private company limited by shares | Live |
| Hydrocell Limited | Private company limited by shares | Live |
| HYDRO-COMPONENTS (ASIA) COMPANY LIMITED | Private company limited by shares | Dissolved |
| HYDROCOMPOS LIMITED | Private company limited by shares | Dissolved |
| HYDROCORE LIMITED | Private company limited by shares | Live |
| LUWASA HYDROCULTURE (H.K.) LIMITED | Private company limited by shares | Dissolved |
| LUWASA HYDROCULTURE PRODUCTS COMPANY LIMITED | Private company limited by shares | Dissolved |
| HYDROCYBER LIMITED | | Live |
| Hydrodigit Limited | Private company limited by shares | Live |
| HYDRODYNAMIC ENTERPRISE COMPANY LIMITED | Private company limited by shares | Live |
| GENERAL HYDRODYNAMICS LIMITED | Private company limited by shares | Dissolved |
| Hydroelektromontazh Co. Limited | Private company limited by shares | Live |
| Hydroen Hong Kong Engineering Co. Limited | Private company limited by shares | Live |
| HYDROER LIMITED | | Live |
| HYDRO-FLUID CONTROLS LIMITED | Private company limited by shares | Live |
| FAR EAST HYDROFOIL COMPANY, LIMITED | Private company limited by shares | Live |
| YUHUA SURFING HYDROFOIL EQUIPMENT (HK) CO., LIMITED | Private company limited by shares | Live |
| Hydroforce Limited | Private company limited by shares | Live |
| HYDROGEN COMPANY LIMITED | Private company limited by shares | Live |
| STP Hydrogen Limited | Private company limited by shares | Live |
| HYDROGEN AGE LIMITED -THE- | Private company limited by shares | Live |
| Hydrogen Atom Company Limited -The- | Private company limited by shares | Live Commenced dormancy on 27-Jan-2016 |
| CHINA HYDROGEN LIMITED | Private company limited by shares | Live |
| China Hydrogen Group Co., Limited | Private company limited by shares | Live |
| China Hydrogen Network Group Co., Limited | | Live |
| CHINA HYDROGEN ENERGY AUTOMOBILE LIMITED | Private company limited by shares | Live |
| China Hydrogen Energy Corporation Limited | | Live |
| CHINA HYDROGEN ENERGY GROUP LIMITED | Private company limited by shares | Live |
| China Hydrogen Energy (HK) Limited | Private company limited by shares | Live |
| China Hydrogen Energy Investment Limited | Private company limited by shares | Live |
| CHINA HYDROGEN ENERGY TECHNOLOGY COMPANY LIMITED | Private company limited by shares | Live |
| Cosmic Hydrogen Energy Limited | | Live |
| Super Hydrogen Energy Company Limited | Private company limited by shares | Live |
| CHINA HYDROGEN ENERGY UNITED LIMITED | Private company limited by shares | Live |
| Hydrogen Happy Limited | Private company limited by shares | Live |
| Pinnacle Fitness (Hydrogen) Company Limited | | Live |
| Green Hydrogen Technology Limited | | Live |
| Hydrogenation IP Company Limited | Private company limited by shares | Live |
| China Hydrogenergy Technology Co., Limited | Private company limited by shares | Live |
| HYDROGLOBE LIMITED | Private company limited by shares | Dissolved |
| FUGRO HYDROGRAPHIC SURVEYS LIMITED | Private company limited by shares | Live |
| Hydrogreen Production Limited | Private company limited by shares | Live |
| Hydrogreens Technology Limited | Private company limited by shares | Live |
| Hydrogro Company Limited | Private company limited by shares | Live |
| HYDROHEALTH LIMITED | Private company limited by shares | Live |
| HYDROHEATING LIMITED | Private company limited by shares | Live |
| HYDROHOUSE COLON HYDROTHERAPY LIMITED | Private company limited by shares | Live |
| HYDROLATINA CO., LIMITED | Private company limited by shares | Live |
| HYDRO-LOC TECHNOLOGY LIMITED | Private company limited by shares | Live |
| HYDROMATE LIMITED | Private company limited by shares | Live |
| HYDROMATE (H.K.) LIMITED | Private company limited by shares | Dissolved |
| Hydromax Limited | Private company limited by shares | Dissolved |
| HYDRO-MAX FITNESS & BEAUTY LIMITED | Private company limited by shares | Dissolved |
| HYDROMET SOUTH EAST ASIA LIMITED | Private company limited by shares | Dissolved |
| China HydroMg Biotechnology Co., Limited | | Live |
| HYDRO-ORIENT LIMITED | Private company limited by shares | Live |
| HYDROPON LIMITED | Private company limited by shares | Dissolved |
| A&T HYDROPONIC LIMITED | Private company limited by shares | Live |
| Hydroponics Limited | Private company limited by shares | Live |
| NL HYDROPONICS LIMITED | Private company limited by shares | Live |
| ECO HYDROPONICS LIMITED | Private company limited by shares | Live |
| GUANGDONG GREEN CYCLE HYDROPONICS CO., LIMITED | Private company limited by shares | Live |
| ZIMBRICK HYDROPONICS LIMITED | Private company limited by shares | Live |
| HYDROPOWER LIMITED | Private company limited by shares | Live |
| NAM THA HYDROPOWER COMPANY LIMITED | Private company limited by shares | Dissolved |
| Wah Fu Hydropower Limited | Private company limited by shares | Live |
| XINHUA HYDROPOWER INVESTMENT CO., LIMITED | Private company limited by shares | Dissolved |
| Xinhua Hydropower Investment Company Limited | Private company limited by shares | Live |
| NICE HYDROPOWER LIMITED | Private company limited by shares | Dissolved |
| Team-Tech Hydropower Limited | Private company limited by shares | Live |
| Hydropure (HK) Limited | Private company limited by shares | Dissolved |
| HYDROPURE (INTERNATIONAL) LIMITED | Private company limited by shares | Live |
| Hydros Argos Investment Limited | Private company limited by shares | Live |
| HYDROSA TRADING LIMITED | Private company limited by shares | Live |
| Hydroscience Resources Limited | Private company limited by shares | Live |
| HydroSeal Limited | Private company limited by shares | Dissolved |
| HYDROSEAL CANADA LIMITED | Private company limited by shares | Live |
| HYDROSEAL CANADA PIPING SYSTEMS CO., LIMITED | Private company limited by shares | Live |
| HYDROSEAL CANADA PRODUCT MANAGEMENT LIMITED | Private company limited by shares | Dissolved |
| HYDROSEAL CORPORATION LIMITED | Private company limited by shares | Live |
| HYDROSOFT LIMITED | Private company limited by shares | Live |