Abstract: This work investigated the effect of Cr and Si on the mechanical properties and oxidation resistance of press hardened steel. Results indicated that the microstructure of the Cr–Si micro-alloyed press hardened steel consisted of lath martensite, M₂₃C₆ carbides, and retained austenite. The retained austenite and carbides are responsible for the increase in elongation of the micro-alloyed steel. In addition, after oxidation at 930°C for 5 min, the thickness of the oxide scales on the Cr–Si micro-alloyed press hardened steel is less than 5 μm, much thinner than 45.50 μm-thick oxide scales on 22MnB5. The oxide scales of the Cr–Si micro-alloyed steel are composed of Fe₂O₃, Fe₃O₄, mixed spinel oxide (FeCr₂O₄ and Fe₂SiO₄), and amorphous SiO₂. Adding Cr and Si significantly reduces the thickness of the oxide scales and prevents the generation of the FeO phase. Due to the increase of spinel FeCr₂O₄ and Fe₂SiO₄ phase in the inner oxide scale and the amorphous SiO₂ close to the substrate, the oxidation resistance of the Cr–Si micro-alloyed press hardened steel is improved.