Magnesium alloy has been generally accepted as an important biodegradable material on cardiovascular stent development for a long time. However, its limited biocompatibility, especially delayed endothelialization process restricts its further application. In this contribution, we modified the Mg-Zn-Y-Nd alloy surface with citric acid and dopamine via a layer-by-layer self-assembly assay, aiming at improving the biocompatibility of the magnesium alloy. The citric acid/dopamine (CA/PDA) layer exhibited a remarkable suppression of platelet activation/aggregation and thrombosis under 15 dyn/cm2 blood flowing. Inhibition on vascular smooth muscle cells growth and macrophages attachment/activation were also observed on this layer. In particular, the CA/PDA layer presented a promoted property for the vascular endothelial cells growth and spreading compared with the bare magnesium alloy, suggesting the pro-endotelialized function. In conclusion, this research may support potential application on surface modification of magnesium alloy based cardiovascular stents for better biocompatibility.