Aim The chronic toxicity of tea polyphenols(TP) in dogs was observed. Methods 18 dogs were randomly divided into high, middle and low dose TP groups and one control group . When TP was given(po) by 650 mg?kg-1?d-1,65 mg?kg-1?d-1,6.5 mg?kg-1?d-1 respectively for 90 d and after TP was stopped for two weeks, the general conditions, ECG, blood routine, urine routine, serum lipids, blood sugar, coagulation time, and hepatic and kidney function were detected respectively. Results These mdices were not different from each other among the 4 groups before, during and after administration of TP . The level of serum total cholesterol was progressively decreased in TP groups. Conclusion TP has no toxic effect on dogs and can decrease the level of serum total cholesterol in normal dogs.