Idiopathic hypogonadotropic hypogonadism (IHH) is gonadal insufficiency caused by hypothalamic gonadotropin-releasing hormone (GnRH) deficiency, which can be accompanied by absence or hyposmia of the sense of smell (also known as Kallmann syndrome). In familial patients, both types of patients with abnormal and normal sense of smell can exist in the same family. The male patients are mostly seen for infertility, secondary sexual characteristics dysplasia and abnormal sexual function, and most of them have no puberty initiation beyond the age of 18. A few patients may have a small amount of pubic hair growth (Tanner pubic hair stage II); 80% of patients are behind their actual age in bone age; 40% of patients have olfactory deficiency or hyposmia; 20% of patients have male breast enlargement; small penis, cryptorchid and vas deferens may be present. Other neurological, musculoskeletal, urinary and cardiovascular diseases may also be associated. The height is generally normal, a few patients are short, obese, and have normal intelligence. The diagnosis of IHH is quite difficult and requires a detailed history of growth and development, perfect imaging of semen, sex hormones, chromosomes, central nervous system and reproductive system, and a systematic physical examination. Patients with a positive family history should undergo a genealogical analysis if possible. This disease has a complex pathogenesis and manifests itself in male infertility patients as severe oligospermia, azoospermia, testicular-penile dysplasia, and inconspicuous secondary sexual characteristics, causing great psychological stress and mental trauma to patients. However, patients do not have to despair and give up on this treatment. There are still effective clinical treatments: 1. Sex hormone replacement therapy Hormone replacement therapy is the basic treatment for IHH. The purpose of sex hormone replacement therapy is to promote the development of secondary sexual characteristics and maintain sexual function, which is commonly used clinically, such as Antel (testosterone undecanoate); 2. Spermatogenesis induction therapy Patients with IHH are first treated with sex hormone replacement therapy, and then with gonadotropins (such as chorionic gonadotropin and urotropic gonadotropin) when they have the demand for fertility, or with GnRH therapy. Prior sex hormone replacement therapy does not affect the efficacy of later spermatogenesis induction therapy. In recent years, male specialists in China have made remarkable achievements in this field, bringing hope to male infertility patients suffering from IHH. Through years of clinical practice and basic research, Professor Li Zheng of Shanghai First People’s Hospital affiliated to Shanghai Jiao Tong University has accumulated rich experience in the treatment of patients with IHH and male infertility. Through comprehensive treatment methods such as gonadotropin-induced spermatogenesis, he has successfully treated many cases of hypogonadotropic hypogonadal male azoospermia patients, enabling them to obtain semen indicators close to those of normal men, and with improved sexual lifestyle, such patients are fully capable of producing their own offspring naturally. This is undoubtedly a blessing for the majority of hypogonadotropic hypogonadal male infertility patients, and I hope that the majority of patients will not lose confidence in the face of the disease.