Objective To compare the effects of different anesthesia on immunologic function during perioperative radical mastectomy in patients having undergone preoperative chemotherapy. Methods Sixty ASA Ⅰ or Ⅱ patients, aged 28-64 yr, weighing 55-70 kg, scheduled for radical mastectomy, were studied. Thirty patients received preoperative chemical therapy for 3-4 weeks were randomly divided into CP group and CS group ( n = 15 each); thirty patients received no chemical therapy were also randomly divided into NCP group and NCS group (n=15 each).Propofol at a rate of 4-6 mg·kg-1·h-1 was infused in group CP and CS and sevoflurane with the end-tidal concentration of 1.5%-2.5% inhaled in group NPC and NCS to maintain anesthesia. Peripheral venous blood samples were taken before chemical therapy, before anesthesia, immediately after operation and at 72 h after operation for determination of the levels of T lymphocyte subsets and NK cells and plasma CK19 mRNA expression (by RT-PCR). CD4+/CD8+ ratio and the micrometastatic rate of the tumor cells were calculated. Results The CD3+ , CD8+ and NK cell level were significantly lower before anesthesia, immediately after operation and at 72 h after operation than before chemical therapy ( P 0.05). Conclusion Sevoflurane combined anesthesia has a stronger inhibitory effect on immunologic function in radical mastectomy patients with preoperative chemotherapy than propofol combined anesthesia. Key words: Anesthetic,inhalation; Immunity; T-lymphocyte; Killer cell, natural