| HYDRACOM INTERACTIVE LIMITED | Private company limited by shares | Live |
| Hong Kong Hydracore Group Development Limited | Private company limited by shares | Live |
| Hydradeli International Limited | Private company limited by shares | Live |
| HYDRAGON LIMITED | Private company limited by shares | Dissolved |
| HYDRAGON LIMITED | Private company limited by shares | Live |
| HYDRAMOTION LIMITED | Private company limited by shares | Live |
| HYDRANGEA MP LIMITED | Private company limited by shares | Live |
| B&M HYDRANGEA LIMITED | Private company limited by shares | Live |
| HYDRANGEA LIMITED | Private company limited by shares | Live |
| HYDRANGEA 81 LIMITED | | Live |
| AHHA Hydrangea I LIMITED | | Live |
| Hydrangea Capital Management Limited | | Live |
| Hydrangea Medical Limited | | Live |
| Hydrangea Trading Limited | Private company limited by shares | Live |
| HYDRANGER ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| Hydrapak Limited | Private company limited by shares | Live |
| HYDRAQUIP (ASIA) LIMITED | Private company limited by shares | Dissolved |
| HYDRAS COMPANY LIMITED | Private company limited by shares | Live |
| HYDRAS CONSULTANTS LIMITED | Private company limited by shares | Live |
| HYDRAS INVESTMENT COMPANY LIMITED | Private company limited by shares | Dissolved |
| Hydrated Skin Beauty Company Limited | | Live |
| SPORTS HYDRATION CO., LIMITED | Private company limited by shares | Dissolved |
| JW HYDRAULIC LIMITED | Private company limited by shares | Live |
| E. N. Hydraulic Limited | Private company limited by shares | Live |
| HKG HYDRAULIC LIMITED | Private company limited by shares | Live |
| GXG Hydraulic Limited | Private company limited by shares | Live |
| CARSUN Hydraulic Solutions Co. Limited | | Live |
| CP Hydraulic Mechanical Company Limited | Private company limited by shares | Live |
| Space Hydraulic Co Limited | Private company limited by shares | Live |
| STM Hydraulics Limited | Private company limited by shares | Live |
| ANWEEL HYDRAULICS CO., LIMITED | Private company limited by shares | Live |
| HUNGER HYDRAULICS (ASIA) LIMITED | Private company limited by shares | Live |
| DENISON HYDRAULICS LIMITED | Private company limited by shares | Live |
| Doyle Pacific Hydraulics Limited | Private company limited by shares | Live |
| ANDA HYDRAULICS HONG KONG LIMITED | Private company limited by shares | Dissolved |
| HALDEX HYDRAULICS (HONG KONG) COMPANY LIMITED | Private company limited by shares | Dissolved |
| KM-HT Automation & Hydraulics Company Limited | Private company limited by shares | Live |
| LINDER HYDRAULICS LIMITED | Private company limited by shares | Live |
| PH HYDRAULICS & MACHINERY (F.E.) LIMITED | Private company limited by shares | Dissolved |
| HYDRAULICS SOLUTIONS LIMITED | Private company limited by shares | Live |
| STAR-UNION HYDRAULICS LIMITED | Private company limited by shares | Live |
| YEOSHE HYDRAULICS LIMITED | Private company limited by shares | Live |
| HYDRAULUX ASIA COMPANY LIMITED | Private company limited by shares | Live |
| HYDRAULX HK LIMITED | Private company limited by shares | Live |
| HYDRCO LIMITED | Private company limited by shares | Dissolved |
| HYDREAM INVESTMENT HOLDING CO., LIMITED | Private company limited by shares | Live |
| Hydreq HK Limited | Private company limited by shares | Live |
| Hydrexia Technology HK Limited | | Live |
| HYDRIADES HK LIMITED | Private company limited by shares | Live |
| HYDRNT LIMITED | Private company limited by shares | Live |
| 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 |