Abstract： Objective To investigate the application value of breast scale membrane marking method to locate breast tumor lesion in neoadjuvant chemotherapy.Methods Before neoadjuvant chemotherapy for 120 cases of breast cancer,adopt scale membrane marking method was used to mark the position and boundaries of breast tumor lesion in the mean time.For non-protuberant breast tumor lesion,scale membrane was adhered directly to the breast and positive mark was made.For tumor lesion with vague boundaries,its boundaries was defined under the direction of ultrasound.For protuberant breast tumor lesion,scale membrane was only adhered to normal mammary skin beyond the tumor lesion and reverse mark was made.After two courses of treatment of TEC scheme,mark was made again and combined with ultrasound,molybdenum target and MRI results to comprehensive judgment of clinical curative efficacy so as to decide whether operation or change to TP scheme for continuous chemotherapy.Before operation,the first marking results were reset and then operation was conducted according to the position and boundaries of the marked tumor lesion.Results There were 26 cases of complete remission,76 cases of partial remission,10 cases of stabile disease and 8 cases of progressive desease.According to mark by scale membrane,breast conserving operations were conducted in 24 cases of complete remission and in 18 cases of partial remission according to position+ boundaries of the tumor lesion and tumor lesion position+ 1.5-2.0 cm beyond the original boundaries of tumor lesion marked by scale membrane,respectively.The simplified radical mastectomy was conducted in other 78 cases according to boundaries of the tumor lesion marked by scale membrane,in which 13 cases had insufficient locally advanced skin edges and adopted abdominal full-thickness free skin flap to cover the wound.Conclusion Tumor lesion location in neoadjuvant chemotherapy for breast cancer and scale membrane positioning method have the advantage of precision and non-invasion,which effectively save normal breat tissues and skin around tumor lesion with high patient compliance and tremendously outmatches traditional coordinate method,body surface tattoo method and mental marker method.Scale membrane marking method is easy to be operated with low cost,which is convenient for popularization and generalization.