Exhibit 8.1

• Ascendium Group Limited (incorporated in the British Virgin Islands)

• Our Medical Services, Ltd. (incorporated in the British Virgin Islands)

• US Proton Therapy Holdings Limited (incorporated in the British Virgin Islands)

• Medstar Overseas Ltd. (incorporated in the British Virgin Islands)

• US Proton Therapy Holdings Limited (Delaware) (incorporated in Delaware, USA)

• China Medical Services Holdings Limited (incorporated in Hong Kong)

• Cyber Medical Network Limited (incorporated in Hong Kong)

• King Cheers Holding Limited (incorporated in Hong Kong)

• China Medstar Pte. Ltd. (incorporated in Singapore)

• CMS Hospital Management Co., Ltd. (incorporated in the PRC)

• Beijing Yundu Internet Technology Co., Ltd. (incorporated in the PRC)

• Shenzhen Aohua Medical Technology & Services Co., Ltd. (incorporated in the PRC)

• Shenzhen Lingdun Technology Co., Ltd. (incorporated in the PRC)

• Tianjin Kangmeng Radiology Equipment Management Co., Ltd. (incorporated in the PRC)

• Chang’an Hospital Co., Ltd. (incorporated in the PRC)

• Medstar (Shanghai) Leasing Co., Ltd. (incorporated in the PRC)

• Guangzhou Huanan Taihe Medical Technology Ltd. (incorporated in the PRC)

• Wanjie Huaxiang Medical Technology Development Co., Ltd. (incorporated in the PRC)

• Beijing Jinweiyikang Technology Co., Ltd (incorporated in the PRC)

• Guangzhou Jinkangshenyou Investment Co., Ltd (incorporated in the PRC)