The birth of a baby boy with only a urethra and no penis may be due to congenital developmental abnormalities caused by genetic factors, environmental factors, etc., such as cryptorchid penis, prepuce and other diseases. 1. cryptogenic penis: it is because of the short appearance of the penile body caused by congenital dysplasia, excessive obesity, surgery or trauma around the penis, almost completely hidden in the pre-pubic soft tissues, it will look like there is only a urethra without a penis. 2. Phimosis: It is due to the adhesion between the foreskin and the head of the penis or scarring of the foreskin or narrowing of the opening of the foreskin in newborn babies, the foreskin can not be upturned to reveal the phenomenon of the head of the penis, and it will look like there is only the opening of the urethra without the penis. This symptom may also be caused by other factors, it is recommended to go to the regular hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor for targeted treatment or treatment.