Objective To observe the clinical effect of gonadotropin releasing hormone analogues in treatment of the girls with idiopathic central precocious puberty(ICPP). Methods Twelve girls with ICPP received therapy with GnRH-A.Before and after the end of treatment for 6 months,secondary sexual characteristics and growth velocity were observed,pelvic ultrasonic examination,X-ray bone age(BA),serum level of E_2 and LHRH stimulating test were detected,and the predicted adult height(PAH) was analysed. Results After treatment,the size of breasts,uterus and ovaries were significantly reduced.The basic and peak levels of serum LH and FSH by LHRH stimulation were also significantly reduced.The ratio of BA/CA(chronology age)was decreased.The PAH was increased. Conclusions GnRH-A can effectively depress the sexual characteristics,reduce the maturation of BA,and also improve the PAH in girls with ICPP.