AIM: To observe the efficacy and adverse reactions of paroxetine in treating irritable bowel syndrome(IBS). METHODS: Sixty three IBS patients with obvious syndromes of depression were randomly divided into two groups: paroxetine group of thirty two patients( M 14, F 18;age 34 a± s 10 a), control group of thirty one patients( M 14, F 17;age 34 a±11 a). Two groups of all patients received nifedipine 10 mg,loperamide 2 mg and oryzanol 20 mg, po , tid. The paroxetine group of patients also received paroxetine 20 mg, po , qd, all for 4 wk, 8 wk. RESULTS: The scores of IPS, SDS and QQL in paroxetine group and control group after treatment wk 4, 8 were 4.8±1.6, 3.8 ±1.4; 40±5, 38±7; 57±13, 70±16, and 6.1±2.0, 5.8± 2.4 ; 52±7, 49±4; 49±16, 51±17, respectively ( P 0.01). The effective rate of the paroxetine group were 75 % and 97 %, respectively, and that of the control group were 48 % and 58 %, respectively. Significant difference was found between two groups ( P 0.05). The adverse reactions of the former were mild. CONCLUSION: Paroxetine is effective and safe in treating IBS patients with obvious syndromes of depression.