Abstract: Objective To observe the role of early function training in function recovery of involved upper extremities of breast cancer patients after operation. Methods One hundred and ten breast cancer patients were divided into function training group（n=60） and control group（n=50） with no difference in age and mobility of involved upper extremities before operation.Patients in function training group and control group were asked to do special and routine function recovery exercises of the involved upper extremities,respectively,before and after operation.Mobility of the involved upper extremities in both groups was measured to observe function recovery of the involved upper extremities on days 4,7 and 12,respectively,after operation. Results Excellent outcomes were achieved in 49（69.01%） and 22（30.99%） patients of the function training and control groups,respectively,after operation.The involved upper extremities of patients in the function training group could perform various activities needed in their daily life although still had a tolerable pain.Those in the control group were sensitive to pain and afraid of doing exercises with their upper extremities.The activity and function recovery of the involved upper extremities were better in training group than in control group（P＜0.05）. Conclusion Early function training of the involved upper extremities of breast cancer patients after operation is beneficial for their function recovery.