The purpose of this study was to verify whether a student’s educational experience has a mediating effect in the process of educational support within the family and educational experience within a school affecting academic achievement of single-parent children, and the differences between children in single parent and two-parent children, using structural equation modeling. Data were obtained from the 2005(1rd)~2011(7th) of KELS2005. This study selected 3,507(310 from single parent families and 3,197 from two parent families) who have been single-parent families and two-parent families from the 1st to the 7th, and took the 2010 CSAT(College Scholastic Ability Test). Data were examined with structural equation modeling and multi-group analysis using AMOS 21.0, and mediating effects were tested using the Sobel test. The results were as follows. First, the single-parent children were reported to receive lower levels at CSAT scores, educational support within the family, educational experience within a school and student’s educational experience than the two-parent children. Second, student’s educational experience did play a mediating role in the process of the educational support within the family and educational experience within a school affecting CSAT scores regarding both single-parent children and two-parent children. Third, as a result of examining for total effect, the variable that most influenced the CSAT scores was student’s educational experience regarding both single-parent children and two-parent children. Fourth, multi-group analysis showed a statistically significant difference between single-parent children and two-parent children in structural equation modeling. Based on the results of this study, it suggested several plans to reduce the educational gap of single-parent children.