This study aimed at revealing the effect of educational modules strategy on the direct and postponed study's achievement of seventh primary grade students in science, in comparison with the conventional approach. The sample of the study consists of (174) male and female students randomly chosen from schools in the city of Mafraq, students are divided into two groups: Control and Experimental. Researchers have developed an educational materials relevant to carry out modules strategy for teaching scientific concepts in the science text book for primary seventh grade, though the development of achievement test to measure the direct and the postponed achievement by the study's sample. The consistency and reliability of the test have been obtained. The study's results revealed that students in the experimental group are superior over students in the control group in both types of achievement. At the same time results showed the lack of difference between male and female students in direct and long-term achievement test. Based upon the study's results, the researcher recommends the necessity to use more modern means to teach students the "Science" domain such as modules strategy, to hold courses and workshops for teachers training on implementing modules strategy. Furthermore, to make available textbook and references which facilities this style of teaching. Finally, to conduct similar studies over different domains, such as physics and mathematics.