There are two ways to measure the size of the penis, one is in a state of weakness and the other is during erection. Penis in the state of weakness, the measurement for the circumcision of the patient should first turn up the foreskin to reveal the head of the penis, and then the measuring tape on top of the pubic symphysis, and then pull the penis, measuring the length of the pubic symphysis to the head of the penis. The ruler is placed against the pubic symphysis when the penis is erect. Measure the length from here to the most distal part of the head of the penis. The length in Asian men is 5-10 centimeters when weak and 10-18 centimeters when erect. When measuring, the end of the ruler near the root of the penis should be pushed towards the pubic bone to push away localized subcutaneous fat. Many men are overly demanding of their penis length and girth and beg their doctors to do surgical reconstruction for them by any means possible. Many of these patients have normal penis size and should not be overly anxious. If there is any abnormality, they should seek medical attention in time to choose the appropriate treatment under the guidance of the doctor.