[Objective] This study aimed to investigate the effects of three kinds of diuretics on the water drinking amount and urination volume of sheep fed with cottonseed hulls. [Method] The method of self-control was adopted. Five two-year-old male Kazak sheep about 40 kg which never had intake of the feeds containing gossypol were selected. The experiment was divided into five periods, namely the control period, a period with the supplement of 300 mg/d of hydrochlorothiazide, a period with the supplement of 200 mg/d of hydrochlorothiazide, a period with the supplement of 350 mg of GY-01 and a period with the supplement of 200 mg of GY-01. The sheep were fed with the concentrate and the cottonseed hulls in the control period, and corresponding diuretics were supplemented in the rest four periods. The water drinking amount, urination volume and the contents of the hormone and ion in the blood were determined in each period. [Result] After 350 mg GY-01 was supplemented, the water drinking amount of each sheep had an increase of 60.14% compared with that of the sheep in the control period and the urination volume was 2.67 times of that of the latter, and the differences were both significant (P0.01). The antidiuretic hormone declined by 32.59% compared with that of the sheep in the control period, with the significant difference (P 0.05). The adrenocorticotropic hormone content increased by 81.93% compared with that of the sheep in the control period and the difference was significant (P0.01). An increase of 28.04% (P 0.05) and 39.39% (P 0.01) was found in the contents of serum potassium and phosphorus respectively compared with that of sheep in the control period. [Conclusion] The diet with supplement of GY-01 can increase the urination volume of livestock fed with the cottonseed hulls, and the most appropriate supplement amount is 200 mg GY-01.