If a boy has only one testicle, it is recommended to go to the hospital for relevant examination to decide how to deal with it.1. Congenital anencephaly, due to unilateral loss of testicle during congenital development, no testicle is found in the body and only one testicle is found, then there is no need for any treatment. Only the unilateral testicle needs to be protected to maintain male androgen secretion and normal spermatogenesis and male fertility.2. Cryptorchidism, which is more common, is a condition in which the testicle has not descended into the scrotum after development, and so it only manifests itself as a unilateral testicle, with the other testicle staying in a place other than the scrotum. If the child is younger than 6 months of age, the child can be monitored and the testicle may descend into the scrotum again as it grows. If the child is older than 6 months, hormone therapy is needed. Human chorionic gonadotropin 1500 mIU/ml can be injected intramuscularly for 10 consecutive times, and the testes will be observed to see if they descend. If the testicle still does not descend into the scrotum with hormonal therapy, surgery for fixation of testicular descent is recommended beyond 1 year of age. This procedure is recommended within 1-2 years of age to avoid prolonged cryptorchidism affecting the spermatogenic epithelium.