Abstract: The research is in intent to explore the psychological mechanism of fair distribution behavior upon toys in the play of indergarten children aged 5-6,on the basis of structured interview and expirical method.The participants are 66 elder kindergarten children.The finding is stated below:(1) the mode of behavior of the toy distribution is divided into three types,fair(20%),unfair(20%),unstable(60%).This implies that age 5-6 is a critical period for nurturing the behavior of collaboration,sharing-with-others,altruism;(2) the participants are able to make self-evaluation accurately not only to the fair behavior conducted,but also the supposed,i.e.,avoid conducting the bad behavior in order not to affect sound self-image,and thereby the psychological mechanism of stable fair behavior is taking the shape;(3) the internalization of morality in self-concept and self-image is valued much.The morality practices in activities therein evaluating self and others'behavior is an effective education measure for the promotion of internalization.

Key words: fair children, unfair children, unstable children, self-image