Abstract: Objective：To analyze the clinical characteristics of male idiopathic hypogonadotropic hypogonadism（IHH）, and to evaluate treatment outcome. Methods：41 infertile men diagnosed as IHH were recruited in this study, including 13 patients with kallmann syndrome and 7 patients with maldescended testes. 35 patients were treated with hCG 2 000 IU plus HMG 150 IU intramuscularly twice a week，for 3 to 24 months. 6 patients rejected treatment. Results：After treatment，all patients felt improved physical strength and increased sex drive，with the secondary sexual development in different degrees. In the 27 patients with treatment over 6 months，the testis volume[（7.1±2.9）mL vs.（9.1±3.9）mL]，FSH level[（1.2±0.8）IU/L vs.（2.0±0.8)IU/L] and testosterone level[（1.1±0.8）nmol/L vs.（12.5±2.7）nmol/L）]were higher significantly than those before treatment（P＜0.05）. 16 patients after treatment were found to have sperm in semen, and 11 patients achieved preganacy. Conclusions：The clinical characteristics of male patients with IHH was testicular dysfunction and infertility. Therapy with hCG plus HMG is efficiency，which can improve the development of second sexual characteristics, and help some patients to achieve eventually fertility.

Key words: Hypogonadism, Kallmann syndrome, Infertility, male, Diagnosis, Therapy