الملخص

The current research aims at defining the effect of Mastery learning strategy on the development of Academic Achievement for Sixth Primary Class pupils in science. The limit of the research was Sixth Primary Class pupils for the academic year 2013-2014) in Nineveh governorate. The sample was (43) students divided into two equal groups ( experimental and control ). To achieve the aim of the research , the researchers made lesson plan for both groups and academic achievement scale as tool of the research. The results showed statistically significant difference in the development of academic achievement and in favor of experimental group.