ABSTRACT: Objective To explore the effect of nicorandil combined with hydration on prevention of contrast-induced nephropathy in patients with chronic renal insufficiency. Methods A total of 52 patients with unstable angina combined with chronic renal insufficiency who were undergoing elective coronary interventional diagnosis and treatment in the department of cardiology were enrolled in this study. They were randomly divided into nicorandil group(26 cases)and control group(26 cases). Compared with the control group, the subjects in the nicorandil group began the daily oral nicorandil 5mg tid 3 days before the coronary diagnosis and treatment. According to the conventional hydration program, the venous blood in the two groups were collected 1 day before operation then 1 day, 2 days, and 3 days after operation. The levels of serum creatinine(Scr), cystatin C(CysC), and GFR were compared between thetwo groups. Results There was no significant difference in GFR, Scr or CysC preoperatively between the nicorandil group and the control group(P>0.05). The level of GFR in the two groups was in decline 1 day, 2 days and 3 days after operation while there was significant difference between postoperative 1 and 2 days and pre-operation, and the index in the nicorandil group was higher than that in the control group 2 days after the operation(P<0.05). Scr and CysC index in the groups were both increased 1 day, 2 days and 3 days after operation while there was significant difference between postoperative 1 and 2 days and pre-operation(P<0.05). The index of Scr and CysC in the nicorandil group was lower than that in the control group 2 days after the operation(P<0.05). No cases of contrast-induced nephropathy in the nicorandil group were found while there were 4 cases in the control group(15.4%), therefore, the difference between the two groups was significant(P<0.05). Conclusions Nicorandil combined with hydration is better than pure hydration on prevention of CIN.