This study, using hierarchical linear models, examined effects of the intervention programs on first-time-full-time students' retention and college cumulative GPA, interacting with students' characteristics, e.g., demographics and college preparedness. Program effects on a three-year trend were also explored. The study results show that the intervention programs had significant effects on retention and college cumulative GPA, and worked better for the first year. Interactions between program type and students' characteristics were also discussed. ********** It is reported that about one fourth of students dropped college after their first year (Mallinckrodt & Sedlacek, 1987; Tinto, 1993; Tinto, Russo, & Kadel, 1994), and about 25% of college graduates got their bachelor degrees from the first college they attended (National Center for Education Statistics, 2004). Retention as well as academic performance is critical to students' success in college; therefore, they are important issues in college administration. Retention is a complex issue involving many different factors. Whether a student departs from an institution is largely a result of the extent to which the student becomes academically and socially connected with the institution. As Tinto's (1975) model indicates, as students are integrated into and become more interdependent with both academic and social elements of a university, the probability that the student will leave the university declines. Astin (1975) also found that involvement was critical to a student's decision to persist or drop out school. In other words, involvement with faculty and student peer groups encourages participation in social and intellectual life of a college and, therefore, helps learning and persistence in college (Astin, 1993; Berger, 1999; Campbell & Campbell, 1997; DeBerard, Spielmans, & Julka, 2004; Nagda, Gregerman, Jonides, von Hippel, & Lerner, 1998; Tinto, 1993). Other factors that may also affect retention and academic performance include institutional type (Chapman & Pascarella, 1983), motivations for attending college (Allen, 1999; Stage, 1989), financial aid (Cabrera, Nora, & Castaneda, 1992; Glynn, Saner, & Miller, 2003; Sandler, 2000; Wetzel, O'Toole, & Peterson, 1999), fulfillment of expectations for college (Braxton, Vesper, & Hosler, 1995; Glynn et al., 2003), sense of community in residence halls (Brower, 1992), self-efficacy (Peterson, 1993), attitudes (Fishbein & Ajzen, 1975; Glynn et al., 2003), and maladaptive coping strategies (DeBerard et al., 2004). In addition, previous research results show that interactions of those factors with students' characteristics, e.g., demographics and college preparedness, play an important role on their success in college. In the literature, most research on students' success in college has used student enrollment data to explore factors affecting students' success in college. Such research has provided much valuable information to college administrators, faculty and staff. As a result, many universities have setup programs based on the theories in the field and the results of research trying to improve students' academic achievement and prevent students from attrition. However, research on intervention program effects somewhat falls behind. Such research would make an important contribute to the literature. This present study is an effort to examine the intervention programs conducted in a Midwest urban university. In an effort to manage the attrition problem and improve students' academic performance, the university has initiated nearly 100 intervention programs, from 2001 to 2003, with the Success Challenge grant funded by the state. The Success Challenge grant has two components: 1) challenging university campuses to enable at-risk students successfully to earn baccalaureate degrees; and 2) challenging university campuses to enable baccalaureate seeking students to complete their degrees in a timely fashion, typically four years. …