Ｏｂｊｅｃｔｉｖｅ　To explore the effect of pentazocine on the changes in cardiac troponin I(cTnI) and its association with calcitonin gene-related peptide(CGRP) in tourniquet-induced leg ischemia/reperfusion(I/R).　Methods　Sixty patients, undergoing elective unilateral leg surgery using tourniquet, under spinal anesthesia, were enrolled and randomly assigned to control group (group C) and pentazocine group(group P)(n=30)， in accordance with a random number table. Patients in group P pretreated with pentazocine 0.5 mg/kg before surgery, while only the same volume of saline was infused intravenously in group C at the same schedule. 5 ml of blood samples were collected from cubital vein in a not transfusion arm immediately before inflating tourniquet (T0), 0.5 h(T1) and 24 h(T2) after tourniquet deflation. Serum concentration of cTnI and CGRP were measured by ELISA.　Results　There was no statistical difference detected in the general information in two groups(P>0.05). Compared with the cTnI at the time of T0 [(0.21±0.06) μg/L] the concentration of cTnI in group C at the time of T1 was not obvious changed(P>0.05), while significantly increased at the time of T2 [(0.28±0.10) μg/L](P<0.05), the concentration of cTnI in group P was no obvious changed at the times of T1 and T2(P>0.05). No significant change in the concentration of CGRP of group C was detected at the time of T1 and T2(P>0.05)， while CGRP in group P was increased significantly at the time of T1[(17.9±2.7) ng/L] and T2[(18.8±2.8) ng/L](P<0.05), compared with CGRP at the time of T0 [(16.9±2.2) ng/L]. Compared the cTnI and CGRP with group C at the times of T1 [(0.23±0.12) μg/L, (16.9±1.9) ng/L] and T2 [(0.28±0.10) μg/L, (16.7±2.6) ng/L], no significant change in the concentration of cTnI of group P was detected at the time of T1(P>0.05), cTnI in group P was decreased significantly at the time of T2[(0.22±0.06) μg/L vs (0.28±0.10) μg/L](P<0.05), CGRP in group P was increased obviously at T1 and at T2(P<0.05).　Conclusions　The results of this study indicates that pentazocine may attenuate myocardial injury induced by leg I/R tourniquet, in which endogenous CGRP may be associated.