The aim of this study is to examine the effect of surface treatments involving shot blasting and paste boronizing on the microstructure, microhardness and density of 316L stainless steel. Shot blasting using glass beads was carried out prior to paste boronizing at fix boronizing temperature and soaking time of 850°C and 8 hours respectively. The results show paste boronizing produces boride layers that consist of FeB and Fe2B on the surface of 316L stainless steel with high hardness. Shot blasting on the other hand creates grain refinement on the metal's surface which increases boron diffusion into the surface and improves the case depth of boride layers formed and also its hardness. Higher shot diameter used in shot blasting also influence in improving the case depth of boride layers produced and hardness of 316L stainless steel. The effect of shot blasting using a higher shot diameter and paste boronizing reduces the density of 316L stainless steel very slightly.