TiO2 coating was obtained by sol-gel method to improve the corrosion resistance of Mg-Ca alloy in human body environment. The corrosion behavior of Mg-1.0 Ca alloy with TiO2 coating was investigated by electrochemical tests and immersion tests in simulated body fluid (SBF). Bare Mg-1.0 Ca alloy suffered serious attack after immersed in simulated body fluid only for 48 h. While for the Mg-1.0 Ca alloy with TiO2 coating, the surface almost maintained intact with only several collapses after immersed in SBF for 168 h. The electrochemical test results showed that the free corrosion current (i (corr)) of Mg-1.0 Ca alloy substrate was 3.3275e-2A/cm(2), while the i (corr) of TiO2 coating was only 1.58549e-5A/cm(2). Therefore, TiO2 coating significantly improved the corrosion resistance of Mg-1.0 Ca alloy in SBF. This enhances the potential of Mg-Ca alloy used as biodegradable orthopedic material.