This paper reports experiments on the rheological behavior of DGEBA epoxy resin filled with blast furnace slag nanoparticles. The study of the variation of stress and viscosity as a function of shear rate is emphasized.The purpose of this study is to investigate the rheological behavior of DGEBA loaded with blast furnace slag (BFS), the selected mixtures cannot exceed 10% in wt%, given the fineness of grinding which SSB= 44.5 m2.g-1. We tested the compositions of DGEBA/%wt blast furnace slag (BFS) at filling ratios of (10, 20, 30, 40 and 50%). Viscosity and shear stress as a function of temperature and filler rate were investigated. In this study, formulations were developed to test the best compositions with favorable rheological behavior for better processing of these matrices.