The current research aims to identify the effect of the mantle of the expert’s strategy on the achievement of science subject for first-grade intermediate students. The researcher followed the experimental approach with two groups (experimental and control) due to its suitability to the nature of the research, where the experiment was applied in (Al-Wasiti Intermediate School for Boys) after conducting equivalence between the two groups (experimental and control) in a number of variables for the safety of the experiment and controlling the variables and accompanying conditions. The total sample consisted of (34) students from the first intermediate grade, with (17) control students and (17) experimental students. The researcher also prepared the necessary plans for the research, as the mantle of the expert strategic plans were created for the experimental group, and teaching plans were prepared according to the usual method, to be studied according to the control group. The achievement test was prepared, consisting of (25) items in its final form, and the researcher presented a set of recommendations and suggestions at the end of the research.