Customer citizenship behavior is a new concept in the field of customer behavior research. It is a valuable and constructive behavior of consumers who are willing to do for the brand out of their roles, which makes the enterprise competitive due to low cost or even zero cost. Therefore, it has gradually attracted widespread concern from domestic and foreign researchers and practitioners in marketing. This paper studies the antecedent variables of consumer citizenship behavior. The connection of self and brand acts as the mediator between the congruence of consumer’s self-image as well as brand image and consumer citizenship behavior. Specifically speaking, neither the consumer’s self-image nor brand image directly affects his/her citizenship behavior but affected by the mediate role of self-brand connection. Only when the consumer voluntarily connects himself/herself with the brand and form high-quality consumer-brand relationship, will consumers voluntarily engage in valuable and constructive behaviors for the brands. In this way, the consumer citizenship behavior forms.