In this study, magnesium alloys with different weight fractions of zinc were fabricated and heat treatment was performed. Microstructure of specimens was characterized by Light Optical Microscope (LOM). Wear tests were applied under different loads in simulated body fluid. Results show that aging process effects tribological behavior of Mg-Zn alloys positively. Mg-3Zn alloy exhibits best wear performance under 2 N load among the samples. Simulated body fluid possesses lubricant properties during wear tests. 16 h heat treated alloys show better wear characteristic than non-heat treatment samples due to decreasing of internal stress. Abrasive and oxidative wear mechanisms are observed by Scanning Electron Microscope (SEM).