Group Company
   - Thai Yamaha Motor Co.,Ltd. 
   - PT. Yamaha Motor Parts Manufacturing Indonesia
   - Yamaha Motor Co.,Ltd.
   - PT. Yamaha Indonesia Motors Manufacturing
   - Yamaha Motor Distribution Singapore Pet. Ltd.

General Company
   - IHI Turbo (Thailand) Co.,Ltd.
   - Auto Alliance Thailand Co.,Ltd.
   - Musashi Auto Parts Co.,Ltd.
   - Siam Toyota Manufacturing Co.,Ltd.
   - Yamada Somboon Co.,Ltd.
   - Isuzu Engine Manufacturing Co.,Ltd.
   - Kitz (Thailand) Co.,Ltd.
   - Bridgestone NCR Co.,Ltd.
   - David Brown Co.,Ltd.
   - Khitkan Co.,Ltd.
   - Raks Manufacturing Co.,Ltd.
   - Siam Hitachai Automotive Products Co.,Ltd.
   - Ford Operation (Thailand) Co.,Ltd.