Exhibit 8.1

Principal Subsidiaries of China Online Education Group

Subsidiaries:

China Online Education (HK) Limited, a Hong Kong company

51Talk English International Limited, a Hong Kong company

Beijing Dasheng Online Technology Co., Ltd., a PRC company

China Online Innovations Inc., a Philippines company

On Demand English Innovations Inc., a Philippines company

Variable Interest Entities:

Beijing Dasheng Zhixing Technology Co., Ltd., a PRC company

Shanghai Zhishi Education Training Co., Ltd., a PRC company

Wuhan Houdezaiwu Online Technology Co., Ltd., a PRC company

Tianjin Dasheng Zhixing Technology Co., Ltd., a PRC company

51Talk English Philippines Corporation, a Philippines company