The main purpose of this study is to synthesize evidence concerning welfare participation behavior and the consequences of the behavior, both for participants and non-participants. Following the life-course theory view of family life, this study incorporates a dynamic model of family process and elaborates historical events into this model. Analyzing data from the NLSY79 (National Longitudinal Survey of Youth), which provides a history of labor force participation and information related to job and family relationships, this study finds that low-income families reach self-sufficiency mostly through marriage, getting a higher wage job, and working longer hours;In terms of determinants of self-sufficiency, the results of logistics regression analyses suggest that having a higher paying job and working more hours will move low-income families into an economically better situation, and that an increase in the hourly wage and hours worked will improve self-sufficiency for low-income families. In addition, the respondent's intelligence level and educational attainment have positive relationships with self-sufficiency and changes in it; being single or with more children makes it more difficult economically compared to being married or having fewer children after controlling for other factors;Based on Chow's F-test, there was a significant change in the behaviors of low-income families during welfare reform, from 1996 to 1998. The average hourly wage is a more important factor than hours worked for attaining higher self-sufficiency over time from 1996 to 2000. Educational attainment and the number of children have important different effects on self-sufficiency and changes in it between 1996 and 1998, while the importance of the respondent's intelligence level and job experience remain relatively the same.