Based on Eccles et al's expectancy-value model of achievement motivation, this study was to investigate the relationship between self-efficacy, control belief, interest, importance-utility and achievement on the process of statistics curriculum at institutes of technology. 476 students, who took statistics and finished ”Statistics learning motivation questionnaire”, were brought into the study survey. Their mid-term scores, as the research data, were analyzed by equation modeling techniques. Results indicated that interest can explain achievement directly, as advocated by the expectancy-value model. The roles of control belief and self-efficacy are as claimed by the expectancy-value model. Self-efficacy can explain achievement through interest. Control belief can explain achievement through self-efficacy and interest. However, the importance-utility cannot explain achievement directly as interest claimed by the task value in the expectancy-value model. The importance-utility must use interest to explain achievement.