The focus of this study was to investigate the relations of family function performance, the expectation gap toward family function and family satisfaction in the 5-6th grade students. Questionnaires were utilized to investigate the 5-6th grade students studying in Taipei County. A total of 660 valid questionnaires were collected. The data collected were analyzed by factor analyses, t-tests, one way ANOVAs, Pearson correlation and multiple linear regressions. The results were as followed:There were six factors measured in factor analyses, including communicative support, affective expression, daily care, problem solving, economic resource, and autonomy. The overall family satisfaction and expectation in family function was high. The overall performance in family function was above average. According to the Pearson correlation, parent's education, the family function performance were positively related to family satisfaction for children; while the expectation gap toward family function was negatively related to family satisfaction for children. From the results of multiple regression, communicative support, daily care, economic resource, autonomy of the expectation gap toward family function had significantly negative prediction on family satisfaction.