Objective To observe the curative effect of opioid-induced-constipation（OIC）with the method of tonifying Qi and nourishing Yin,and explore its possible mechanism.Methods 60 cases of patients with stage Ⅲ a and Ⅲbliver cancer treated from January to December 2018 who were all complicated with OIC were divided into observation group and control group of 30 cases in each group with stratified random sampling method.Both groups were given transcatheter arterial chemoembolization and oxycodone for pain relief as the basic treatment.The control group was also given lactulose oral liquid 10 mL/time and 3 times a day.While the observation group was also treated with Chinese herbal medicines for tonifying Qi and Yin.The course of treatment were both 4 weeks.The improvement of clinical symptoms,BFI,pelvic floor electromyography and the expression of serum β-arrestin2 and related AQPs were observed and the the adverse reactions during the treatment were collected.Results 1.The effective rate of the observation group and the control group were 73. 3% 和 46. 7% respectively,BFI was lowered in both groups,the observation group improved more significantly（all P<0. 05）; 2. After treatment,the maximum amplitude of rapid contraction in the observation group was increased,while the coefficient of variation of sustained contraction and the coefficient of variation of durable contraction decreased（all P<0.05）. There was no significant difference between the amplitude of the front baseline and the amplitude of the rear baseline（P>0.05）. 3. Compared with the blank group before treatment,β-arrestin2 and serum AQP3,AQP4 and AQP8 in the patient ’s serum were significantly improved,and AQP2 reduced in the observation group（P<0. 05）. After treatment,the expressions of serumβ-arrestin2,AQP3,AQP4 and AQP8 of the observation group decreased（P<0. 05）,and the expression of AQP2 increased（P<0. 05）,while there was no significant difference in the indexes in the control group（P>0. 05）. Conclusion The method of tonifying Qi and nourishing Yin can improve the clinical symptoms, BFI, pelvic floor muscle strength and motor coordination, and regulate the expression of serum β-arrestin2 and related AQPs by tonifying Qi and Yin for patients with OIC.