Questionnaire method was used to study co-parenting structure with a sample 775 of couples of school-age children in Dalian of China. At the same time, through situational observations, coding analyses and evaluating for 28 nuclear families’ parents, co-parenting behavior’s actuality and characteristics were shown. The results show that (1) Three factors covered in co-parenting structure: Harmonious-support, active-involvement and opposite-conflict; (2) Superior reliability and validity in self-designed, parental reported co-parenting questionnaire, a reliable test instrument measuring and analyzing the co-parenting behavior, three factors related model, turn to be reasonable and valid.