This research aimed to identify the effectiveness of a strategy ofactivating previous knowledge in the tendency towards the subject of physics of second intermediate grade students, to verify the aim of the research, the researchers used experimental design with two equivalent groups (experimentation and control), as the research sample included (69) students, ( 33) students for the experimental group and (36) students for the control group, the research instrument was a scale of students' tendencytowards the subject of physics prepared by the researchers consisting of (25) items, after verification of its validity and reliability was applied at the end of the experiment, SPSS was used to calculate the means , Standard deviation, percentages, t-test value , Pearson correlation coefficient, Cronbach’s alpha coefficient, and the effect size calculation equation (2) . Results showed a statistical significant difference between the two groupsmean scores and the control group's mean scores in favor of the experimentation group .In light of the results the researchers came out with some conclusions, recommendations and proposals.

Activating ; Knowledge ; Previous ; Tendency