AbstractAlthough the adsorption of proteins on the Mg surface was ascribed to be the main reason for the effect of proteins on magnesium (Mg) degradation, few studies about the adsorption of proteins on the Mg surface were performed due to the labile circumstances during immersion. In the present study, the adsorption of bovine serum albumin (BSA) and fibrinogen (Fib) on the Mg surface during and after immersion was extensively investigated in different media for the first time. The results revealed that BSA and Fib showed a similar adsorption trend on the Mg surface during and after immersion, and they adsorbed more on the Mg surface in Hank’s balanced salt solution (HBSS) than in Dulbecco’s modified Eagle medium Glutamax-I (DMEM). The possible influence factors for protein adsorption, such as pH, surface roughness, and wettability, were considered to elucidate different adsorption in HBSS and DMEM. It was found that the participation of Ca2+ in the formation of degradation products largely affected the degradation rate of Mg, changed surface roughness, compactness, and surface charge during immersion, which largely suppressed the adsorption of proteins on the Mg surface.