In this talk, we will present a two-component model of the γ-ray emission which assumes that the total γ-ray output of blazars consists of relativistically beamed and unbeamed components. 584 Fermi/LAT-blazars are listed in our compiled catalogue. This idea leverages the correlation between the radio core-dominance parameter and the γ-ray beaming factor. We firstly propose a so-called "γ-ray core-dominance parameter" and we successful divide the γ-ray emission into beamed and unbeamed contributions theoretically for those 584 sources. Our analysis confirms that the γ-ray emission in blazars is mainly from the beamed component.