Boys testicle size varies with age. The normal range of testicular size in boys is specifically referenced to the following data for boys descending to the scrotum at 9 months of age or after delivery. When boys are 5-9 years old, testicular volume is 1-3mL, length diameter <2.5cm; when boys are 9-11 years old, testicular volume is 4-8ml, length diameter 2.5-3cm; when boys are 11-14 years old, testicular volume is 10-15mL, length diameter 3-3.5cm; when boys are 14-16 years old, testicular volume is 15-20mL, length diameter 4.5cm. The development process can be in accordance with the above standards on the male testicular size of the initial judgment, such as the emergence of large differences, need to be analyzed according to the specific situation of the child, it is recommended to go to the hospital, you can check the scrotum ultrasound, testicular epididymal ultrasound, which will help to clarify the judgment, and related treatment.