Abstract: Objective: To detect the correlation between bone age index (BAI) and index of GnRH stimulation tests for precocious children. Methods: 38 girls who had been diagnosed sexual precocity did GnRH stimulation tests and Bone age be determined by left hand and wrist X-ray, CHN method was used to determine the bone age, BAI equal to the bone age dividing the actual age, according to the clinical symptom and the results of laboratory, the 38 girls were divided into idiopathic precocious puberty (ICPP) group and peripheral precocious puberty (PPP) group. The correlation of BAI and index of GnRH stimulation tests were analyzed between the two groups. Results: the BAI and the LH peak 、FSH peak、LH/ FSH peak ratio had correlation in the idiopathic precocious puberty group ,but in the peripheral precocious puberty group the correlation was not existed. Conclusion: the higher BAI, the more possible to be central precocious puberty, the more necessary to do GnRH stimulation test.

Key words: bone age index, sexual precocity, gonadotropic releasing hormone stimulation test, children, diagnose