Sub-adult monkeys are independent monkeys that have left their mothers but have not yet matured sexually. According to relevant public information, sub-adult monkeys are independent of female monkeys, but they are not sexually mature. Sub-adult golden monkey is the easiest training period in the whole growth stage of golden monkey, and the male sub-adult does not grow canine teeth, which reduces the training risk and is close to human children aged 3 to 4.