This study explores the explicit academic language teaching effect on written scientific explanation. Two proposals for science unit intervention focusing on writtenscientific explanation was applied to four different fourth grade Chilean classrooms, one of them including explicit teaching of academic language resources integration at lexico-grammatical level in the different organizational phases of the written scientific explanation. 179 students wrote a scientific explanation at the beginning and at the end of each unit. A significant larger number of academic language resources as well as of significant correlations in the students’ productions after the explicit teaching of embedded resources intervention was found. This study gives preliminary evidence of the relevance of the explicit teaching of academic language to help student master written academic genres