Background and Purpose: Today, the quality of students' performance in various subjects, such as mathematics that is important in selecting the field of study, is one of the basic issues in the educational system. The purpose of the present study was to investigate how the expectancy– value Motivational model affects the intrinsic and extrinsic educational Motivation, educational engagement (Motivational strategies, learning strategies), and Academic performance of students in mathematics. Method: The statistical population consisted of all 8th grade male students in Dezful city. 50 students were selected by multi-stage cluster sampling and placed in two experimental and control groups (25 students in each group). The expectation-value Motivation model was implemented in the experimental group, while the control group received no training. In order to collect data in this study, Harter's classroom Motivational scale (2005) and motivated strategies for learning questionnaire (Pintrich & DeGroot, 1990) were used. Results: The results of covariance analysis showed that there was a significant difference between the two groups in the intrinsic educational Motivation variables, Motivational engagement, cognitive engagement, and Academic performance (P <0. 01). Conclusion: Based on the results of this study, the use of expectation-value Motivation model will have a positive effect on Academic Motivation, educational engagement, and Academic performance.