The roles of Supplemental Nutrition Assistance Program (SNAP) and parental resources in household food insecurity are investigated with a endogenous ordered probability model. Data for husband-wife families with children from the 2010 and 2011 Current Population Survey are used. SNAP participation is found to reduce the probability of household food insecurity among adults by 8.8%,increases the probability of being low food security among children by 6.1%,and increases the probability of being very low food security among children by 2.7%.Parental resource and socio-demographic variables also play important roles in determining SNAP participation and household food insecurity.