Dynamic Compression Plate (DCP) is one of a biomaterials plate, which is used for joining fractured/broken bones. Stainless steel 316L (SS 316L) is widely used in medical applications. Due to SS 316L easy fabrication, available in the market, cheap, and good corrosion resistance. However, SS 316L should be upgraded its surface mechanical properties for implantable materials. Shot peening is one of the methods to increase mechanical properties of SS 316L. This research aims to investigate the effect of shot peening steel ball variation before drilling machining on microstructure, surface roughness, wettability, microhardness, and thickness of stainless steel 316L. In this research, DCP is designed for joining shin bone (tibia) in dimension 105 mm x 12 mm x 4 mm. Shot peening process was conducted in 10 minutes at the pressure of 6 bar with steel ball of 0,4 mm, 0,6 mm, 0,7 mm, and 100 mm nozzle-to-plate distance. After was the plate got drilling machining is done by making 6 holes, 5 mm diameter each, with holes aligned to the plate. The result shows that the shot peening treatment before drilling machining of SS 316L DCP was able to increase the mechanical properties. Microstructure of plate has change on the surface and sub-surface. Surface roughness increased from 0,83 μm to 2,19 μm. Micro hardness increased 274,3 HVN to 358,68 HVN. Wettability is reduced from 84,33˚ to 76,35˚. Thickness is reduced from 3,81 mm to 3,64 mm. The hole geometry due to drilling process after shot peening treatment is not too affected.