Since self-concept and interest are related to educational outcome directly, they have received considerable attention in educational research (e.g. Marsh & Shavelson, 1985; Hidi, & McLaren, 1990; Eccles et al., 1993; Weingburgh, 1998; Marsh, Byrne, & Yeung, 1999). These are two important predictors of future behavior including academic achievement. Therefore, the factors which affect self-concept and interest need to be investigated. The main purpose of this study is to determine whether gender and grade have any effect on students' academic self-concept and academic interest in science. The research questions areo Do males and females differ in terms of over all academic self-concept in science? o Do males and females differ in terms of over all academic interest in science? o Does grade make differences on students' academic self-concept in science? o Does grade make differences on students' academic interest in science?An instrument consists of two parts was used to measure the variables of this study. The first part which consists of 6 items (items 1 to 6) was used to measure students' academic self-concept (Marsh, 1990 as cited in Corbiére, Fraccaroli, Mbekou, & Perron, 2006). The second part which consists of 6 items (items 6 to 12) was used to measure students' academic interest (Corbiére & Mbekou, 1997 as cited in Corbiére, Fraccaroli, Mbekou, & Perron, 2006). In order to investigate whether gender and grade have any effect on students' academic self-concept and academic interest in science, 502 students from 4th grade to 8th grade were randomly selected. Two-way MANOVA was conducted as the design of this study.The results indicate that there is no interaction between two independent variables which are gender and students' grade. In addition, gender has no effect on students' academic self-concept and academic interest in science. Whereas students' grade has an effect of at least one of the groups on the set of academic self-concept and academic interest in science is different from the others. 4th grade is significantly different from all other grades except the 5th grade. 5th grade is significantly different from all other grades except the 4th grade. 6th grade is significantly different from all other grades. 7th grade is significantly different from all other grades except the 8th grade. 8th grade is significantly different from all other grades except the 7th grade. Moreover there is a significantly difference in academic interest in science between 8th grade and all other grades.Corbiére, M., & Mbekou, V. (1997). Academic interest questionnaire. Unpublished document. Vancouver (BC), Canada, University of British Columbia. Corbiére, M., Fraccaroli, F., Mbekou, V., & Perron, J. (2006). Academic self-concept and academic interest measurement: A multi-sample European study. European Journal of Psychology of Education, vol XXI, (n0 1), 3-15. Eccles, J.S., Wigfield, A., Harold, R.D., Blumenfeld, P. (1993). Age and gender differences in children's self- and task perceptions during elementary school. Child Development, 64, 830-847. Hidi, S.E., & McLaren, J. A. (1990). Motivational factors and writing : the role of topic interestingness. Europen Journal of Psychology of Educational, 6 (2), 187-197. Marsh, H.W. (1990). The structure of academic self-concept: The Marsh/Shavelson model. Journal of Educational Psychology, 82, 623-636. Marsh, H.W., Byrne, B.M., & Yeung, A.S. (1999). Causal ordering of academic self-concept and achievement: Reanalysis of a pioneering study and revised recommendations. Educational Psychologist, 34(3), 155-167. Marsh, H. W., & Shavelson, R. (1985). Self-concept: Its multifaced, hierarchical structure. Educational Psychologist, 20, 107-123.Weinburgh, M. H. (1998). Gender, ethnicity, and grade level as predictors of middle school students' attitudes toward science. The paper presented at the Annual International Conference of the Association for the Education of Teachers in Science, Minnesota, USA. A national journal.