Sexual identity disorder refers to children’s perception of their own gender and behaviors that are contrary to their true anatomical characteristics. That is, a male (female) child prefers to dress in female (male) clothes, behaves as if he/she were a female (male) child) or persistently denies that his/her body has anatomical characteristics of the male (female) sex. Normal children are able to distinguish vaguely whether other children are the same as they are or different from them at about 2 years of age, and tend to prefer children of the same sex. At about 3 years of age, they can recognize themselves as male or female. At 3 years of age children choose toys that are similar to their own gender. By the age of 4, they can correctly identify whether a doll is female or male. On the other hand, there are gender differences in the behavior of boys and girls since early childhood, e.g., girls like to play with dolls, while boys like to play with tanks and guns. Generally at the age of 2 years its play behavior has gender differences, to 3 ~ 4 years old, it is very obvious. And the development of true sexuality comes after puberty. Those with sexual recognition disorder, on the other hand, are still unable to recognize their sexual identity and/or behave like the opposite sex by the appropriate age. The disorder is seen in children between the ages of 3 and 7, but is not common. It can be cured by a change in environment if it is due only to poor environmental upbringing. Those with a marked tendency toward disorder or anatomical and physiological factors that cannot be easily removed are often not easily treated.Green (1987) followed 44 cases of male identification disorder and control children with a mean age at first diagnosis of 7.1 years (4 to 12 years). The average age at follow-up was 18.9 years (14-24 years). Seventy-five percent of the children had bisexual or homosexual fantasies, and 80% had homosexual or bisexual sexual behavior. In the control group, none of the patients had homosexual or bisexual fantasies, and only one case (4%) had homosexual behavior. The above data show that there are still a considerable number of homosexuals in this group of patients when they become adults. Children should be trained from an early age to correctly identify their gender. Boys should wear men’s clothes and have masculine toys, such as guns, cars, airplanes, balls and blocks. At an early age, they should be allowed to observe and imitate their father’s courageous behavior and be in the company of boys. Girls should wear women’s clothes and play with dolls. At an early age, they should be in the company of girls. Parents should not mold the child’s gender based on their own preferences, which is harmful to the development of children’s sexual identity. At the same time, from an early age, it is important to avoid putting children in a state of high anxiety and tension. Especially for children who are inclined to the opposite sex at an early age, early attention should be paid to education. For example, boys who are too quiet and shy should be trained to be active and brave. For those with existing disorders, behavioral therapy, cognitive therapy and psychoanalytic therapy can be used. For those whose parents are not psychologically healthy enough or whose families are in conflict, attention should be paid to the psychological treatment of the parents or to the development of family therapy. For those with physiological and anatomical abnormalities, the original disease should be actively treated.