Recently natural fiber composites are overtaking the place of synthetic fiber composites forrnmany applications, so it seems crucial to model interfacial shear strength of it and study the loadrntransfer efficiency between the fiber and the resin, which plays a significant role in determiningrnthe mechanical properties of the fiber reinforcement which the is fiber-epoxy matrix. In thisrnpaper two fiber; Pineapple fiber and kapok, which has the highest and lowest youngâ€™s modulusrnare chosen. Twelve models, six for each kind of fiber, are developed using ABAQUS softwarernconsidering different conditions, such as various fiber embedment lengths, fiber diameter, andrnvoid sizes for fiber pullout failure of the interface between the fibers and epoxy. Parametersrnstudied are fiber embedded length of 3 mm and 0.1 mm; fiber diameter 48 for pineapple andrnKapok fiber with a length of 1mm and 0.1 mm with a diameter of 33 is taken. The effect ofrnthe presence of voids on the interface of fiber and epoxy is studied. The average interfacial shearrnstrength obtained, between epoxy and fiber interface, are for pineapple andrn for kapok. This study shows the interfacial shear strength is dependent on thernelastic modulus and density of the fiber but the change in the interfacial contact surface area duernto change in embedded length of fiber has no significant effect on the interfacial shear strengthrnvalue. But the change in diameter of the fiber and void ratio affects interfacial shear strength.rnRather the presence of void does have a positive effect on the incremental of the value interfacialrnshear strength.