Abstract：Objective：To observe the clinical effect of Xiakucao Xiaoru prescription for precocious puberty in children and its effect on levels of sex hormones in serum. Methods： A total of 47 cases of children with precocious puberty were randomly divided into the control group and the treatment group， 23 and 24 cases in each group respectively. The control group was treated with Zhibai Dihuang pills， and the treatment group was treated with Xiakucao Xiaoru prescription. Both groups were treated for six months. The clinical effect and the changes of levels of sex hormones in serum including progesterone(P)， testosterone(T)， prolactin(PRL)， estradiol(E2)， follicle stimulating hormone(FSH) and luteinizing hormone (LH) before and after treatment in the two groups were observed and compared. Results：The total effective rate was 91.67% in the observation group and 73.91% in the control group， the difference being significant(P＜0.05). After treatment， the levels of T，P and FSH in serum in the two groups were increased when compared with those before treatment(P＜0.05)， and the levels of PRL， E2 and LH in serum were decreased when compared with those before treatment(P＜0.05)； the improvement of the above indexes in the observation group was more significant than that in the control group(P＜0.05). Conclusion：Xiakucao Xiaoru prescription in treating precocious puberty has significant effect and can effectively regulate the disorders of sex hormones in serum，whose curative effect is better than that of Zhibai Dihuang pills.