| POWER FORCE SYSTERMS LIMITED | Private company limited by shares | Live |
| MIN SYSTERS TEHUS LIMITED | Private company limited by shares | Dissolved |
| SYSTEX LIMITED | Private company limited by shares | Dissolved |
| SYSTEX ENGINEERING COMPANY LIMITED | Private company limited by shares | Dissolved |
| Systex Solutions (HK) Limited | Private company limited by shares | Live |
| SYSTEX INFORMATION (H.K.) LIMITED | Private company limited by shares | Live |
| SYSTEX INTERNATIONAL GROUP LIMITED | Private company limited by shares | Live |
| SYSTIME LIMITED | Private company limited by shares | Dissolved |
| Systime Limited | Private company limited by shares | Live |
| SYSTOMIC LIMITED | Private company limited by shares | Dissolved |
| SYSTON LIMITED | Private company limited by shares | Dissolved |
| SYSTON COMPONENTS (ASIA) LIMITED | Private company limited by shares | Dissolved |
| SYSTONE INTERNATIONAL LIMITED | Private company limited by shares | Live |
| SYSTRA ASIA PACIFIC LIMITED | Private company limited by shares | Live |
| Systra Technologies Limited | Private company limited by shares | Live |
| SYSTROL MANUFACTURING COMPANY LIMITED | Private company limited by shares | Dissolved |
| SYSTROME NETWORKS LIMITED | Private company limited by shares | Live |
| SYSTRON LIMITED | Private company limited by shares | Dissolved |
| Systronic I.T. Solutions Limited | Private company limited by shares | Live |
| GL SYSU Hospital HK Holdings Limited | Private company limited by shares | Live |
| SYS-UNITED LIMITED | Private company limited by shares | Dissolved |
| Sysvideo Technology Limited | Private company limited by shares | Live |
| SYSVR LIMITED | | Live |
| SYSVR TECHNOLOGY LIMITED | Private company limited by shares | Live |
| SYSWARD ENTERPRISE LIMITED | Private company limited by shares | Dissolved |
| SYSWAVE LIMITED | Private company limited by shares | Live |
| SYSWELL INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| SYSWIN Limited | Private company limited by shares | Live |
| Hong Kong Syswin Co., Limited | | Live |
| SYSWIN INTERNATIONAL PROPERTY MANAGEMENT LIMITED | Private company limited by shares | Dissolved |
| A & J SYSWORKS LIMITED | Private company limited by shares | Dissolved |
| SYSY District Company Limited | Private company limited by shares | Dissolved |
| SYTA TECHNOLOGY LIMITED | Private company limited by shares | Live |
| SYTAC LIMITED | Private company limited by shares | Dissolved |
| SYTC HK Limited | | Live |
| SYTECH LIMITED | Private company limited by shares | Live |
| SYTEK SOLUTION LIMITED | Private company limited by shares | Live |
| SYTEX LIMITED | Private company limited by shares | Dissolved |
| SYTEX LIMITED | Private company limited by shares | Live |
| SYTHE LIMITED | Private company limited by shares | Dissolved |
| SYTHERA TRADE ASIA LIMITED | Private company limited by shares | Dissolved |
| SYTHNOSIS INVESTMENT HONG KONG LIMITED | Private company limited by shares | Dissolved |
| SYTING TRADE LIMITED | | Live |
| SYTNA LIMITED | Private company limited by shares | Live |
| SYTON TECHNOLOGY LIMITED | Private company limited by shares | Live |
| HK SYTONG LIMITED | Private company limited by shares | Live |
| Sytool Industrial Limited | Private company limited by shares | Live |
| SYT-SYSTEMS LIMITED | Private company limited by shares | Dissolved |
| Sytun Machinery Limited | Private company limited by shares | Live |
| SYTYS Co., Limited | Private company limited by shares | Live |
| SYUAN SIN LIMITED | Private company limited by shares | Live |
| Syuan (HK) Limited | Private company limited by shares | Live |
| Ya Syuan International Limited | Private company limited by shares | Live |
| S-Yuan Electronic Technology Limited | | Live |
| HK SYUAN TRADE LIMITED | | Live |
| SYUAN TRADING CO., LIMITED | Private company limited by shares | Live |
| SYUAN TRADING CO., LIMITED | Private company limited by shares | Live |
| SYUAN INTERNATIONAL TRADING CO., LIMITED | Private company limited by shares | Live |
| SYUANTES LIMITED | | Live |
| SYUE Company Limited | Private company limited by shares | Live |
| SYUEN PUBLISHING LIMITED | Private company limited by shares | Dissolved |
| Syuen Resources (M) Investment Limited | Private company limited by shares | Live |
| Syuhai Limited | Private company limited by shares | Live |
| SYUKEE HAIR CO., LIMITED | Private company limited by shares | Live |
| SYU.LAIMEIZI (HONGKONG) INTERNATIONAL BIOTECHENOLOGY CO., LIMITED | Private company limited by shares | Live |
| SYUM LIMITED | Private company limited by shares | Dissolved |
| SyunDak Trading (Hong Kong) Co. Limited | Private company limited by shares | Live |
| Syuno Beauty Technology Limited | | Live |
| SYUNZAI CIRCULATION HONG KONG LIMITED | Private company limited by shares | Dissolved |
| SYU'S TRADING CO. LIMITED | Private company limited by shares | Live |
| HK SYUTPAAU INT'L GROUP LIMITED | Private company limited by shares | Live |
| SYUYU INDUSTRY LIMITED | Private company limited by shares | Live |
| SYVEX LIMITED | Private company limited by shares | Dissolved |
| Syvih Limited | | Live |
| SYVISION TECHNOLOGY CO., LIMITED | Private company limited by shares | Live |
| SYWOP TRADE LIMITED | Private company limited by shares | Live |
| SYWY TECHNOLOGY LIMITED | Private company limited by shares | Live |
| HONG KONG SYXNO INTERNATIONAL GROUP LIMITED | Private company limited by shares | Live |
| HK SYXY LIMITED | Private company limited by shares | Live |
| SYYZ LIMITED | Private company limited by shares | Live |
| SYZF COMPANY LIMITED | Private company limited by shares | Live |
| SYZS International (HK) Group Limited | | Live |
| SyZyGy Limited | Private company limited by shares | Live |
| SYZYGY POWER CO., LIMITED | Private company limited by shares | Dissolved |
| SYZYGY Cosmetics Limited | Private company limited by shares | Live |
| Syzygy Design Limited | | Live |
| Syzygy Life Limited | | Live |
| Syzygy Travel Limited | Private company limited by shares | Live |
| HONGKONG SYZZ INDUSTRY CO., LIMITED | Private company limited by shares | Live |
| SYZZ TECHNOLOG LIMITED | | Live |