Ｏｂｊｅｃｔｉｖｅ　To investigate the effects of different doses of dexmedetomidine (Dex) combined with ropivacaine for ultrasound-guided transversus abdominis plane (TAP) block on stress response in patients undergoing laparoscopic gynecological surgery.　Methods　One hundred and twenty-five patients who were scheduled to undergo laparoscopic gynecological surgery under general anesthesia were randomly divided into five groups (n=25): group A (control group) where subjects didn′t received TAP block; group B where subjects received 0.2% ropivacaine (a total volume of 60 ml) perineurally for TAP block alone; group C to E where subjects received 0.2% ropivacaine combined with 0.25, 0.50, 1.00 μg/kg Dex (a total volume of 60 ml) perineurally for TAP block, respectively. General anesthesia was induced and maintained after TAP block was successful. Mean arterial pressure (MAP) and heart rate were recorded prior to nerve block (T0), prior to pneumoperitoneum (T1), 1 h after pneumoperitoneum (T2), and 10 min after extubation (T3). Meanwhile, venous blood sample were collected to detect the levels of plasma cortisol (Cor), norepinephrine (NE) and blood glucose (Glu). Recovery time from anesthesia, the total consumption of propofol and remifentanil during the operation were recorded. Incidences of intraoperative adverse reactions and use of postoperative analgesics were calculated.　Results　Compared with group A, remarkable decreases were found in MAP, heart rate, plasma Cor, NE and Glu levels and the total intraoperative consumption of propofol and remifentanil in groups B, C, D and E from T1 to T3 (P<0.05). Compared with T0, marked increases were found in MAP and heart rate in group A and plasma Cor, NE and Glu levels in groups A, B and C from T1 to T3 (P<0.05). The incidence of bradycardia was higher in group E than those in other groups (P<0.05). The use of postoperative analgesics were less frequent in groups D and E than those in other groups (P<0.05). There was no significant difference among the five groups about recovery time from anesthesia (P>0.05).　Conclusions　The addition of Dex to ropivacaine for ultrasound-guided TAP block can inhibit stress response in patients undergoing laparoscopic gynecological surgery, where 0.50 μg/kg dexmedetomidine is a suitable dosage.