This work focuses on studying the effect of Data Seeds (DS) and Olive Seeds (OS) particles on tensile and impact properties of epoxy resin. Olive and dates seeds powder were added to epoxy matrix at weight fraction (0, 8, 13, &18 wt %) with grain size (300, 450 & 600µm). The composite specimens were prepared by Hand-Lay-up technique and cut according to standard test. It's found the higher value of modulus of elasticity and tensile strength happened at (=18 wt %) and grain size (300µm) for specimens reinforced with olive seeds powder, but obtained the lower percentage of elongation at break, impact strength and fracture toughness at this value. Also the mathematical model results show that the weight fraction of powder have higher effect than grain size on properties.