The purpose of this study was to enhance descriptive writing skills and self-efficacy of EFL sixth grade primary pupils through an Interactive Writing Approach Based Strategy. The researcher adopted the quasi- experimental design. The participants of the study included 72 pupils who were randomly drawn and divided into two groups: the control group (N= 36) and the experimental group (N= 36) from Al-Asslogi primary school, Sharkia Governorate in the school year 2015 ∕ 2016. The experimental group was taught by the use of an Interactive writing Approach Based Strategy. On the other hand, the control group received regular instruction. The instruments of the study were: a) an EFL descriptive writing test to measure the development in the experimental groups' pupils, c) writing skills questionnaire, e) writing skill test(self-efficacy) to measure enhancement of identifying the writing in the experimental group pupils, f) writing scoring rubric and The strategy was taught over period three months approximately. The results indicated that there was statistical difference between the mean scores of the experimental and those of the control group in their descriptive writing and self-efficacy . It was concluded that the present study provide evidence for the effect of the Interactive Writing Approach Based Strategy to develop descriptive writing skills and self-efficacy.