Objective To explore the effects of family dynamics on lymphedema postoperative rehabilitation , positivity and the quality of life ( QOL) in breast cancer patients after surgery .Methods A total of 130 breast cancer patients who received rehabilitation therapy were investigated by family dynamics questionnaire , positive and negative affect scales , and QOL questionnaire .The patients are followed up for 8 weeks, and the clinical features of patients with different family dynamics , the difference in the positive rate of rehabilitation patients , the improvement degree of obstructive lymphedema after treatment and their QOL were compared.The effects of family dynamics on lymphedema rehabilitation and QOL in breast cancer patients after surgery was explored on the basis of logistic regression and multivariate linear regression methods . Results After rehabilitation, the improvement degree of lymphedema in patients with high family dynamics was apparently higher than those patients with low dynamics (P<0.05).Multiariable logistic regression analysis showed that:high family dynamics , the positivity before rehabilitation treatment , divorced or widowed , high-grade pathology and elder were independent factors of improving the lymphedema .Multiple linear regressions analysis showed that: high family dynamics, age, marital status, positivity before rehabilitation and family annual income were independent factors of QOL .There was a positive correlation between the family dynamics score and the improvement degree of positivity of rehabilitation ( r=0.241, P<0.01) as well as QOL ( r=0.358, P<0.01).Conclusions The positivity of breast cancer patients in lymphedema rehabilitation is low . The family dynamics still need to be improved and family dynamics is an influencing factor of positivity in rehabilitation .Family dynamics provides a new way for improving the positivity of rehabilitation .