Abstract: The objectives of this study were to prepare pitavastatin-loaded poly lactic-co-glycolic acid nanoparticles(PLGA), to characterize their pharmaceutical properties, to conduct in vitro drug-release from the nanoparticles, and to observe the effects on the proliferation of endothelial progenitor cells. Both pitavastatin-loaded PLGA and blank PLGA nanoparticles were prepared using emulsion-solvent diffusion method with PLGA being carrier materials. Morphology of the nanoparticles was observed by scanning electron microscopy(SEM), and particle size was analyzed by laser nanometer particle size analyzer. The drug loading and encapsulation efficiency were assayed using high-performance liquid phase. Impact of blank and pitavastatin-loaded nanoparticles on the viability of endothelial progenitor cells was investigated by CCK8 method. Pitavastatin-loaded PLGA nanoparticles exhibited the structure with spherical shape, smooth surface and average diameter of(230. 1±45)nm. The drug loading capacity and encapsulation efficiency were(10. 00±1. 83)% and(35. 54±5. 40)%, respectively. In vitro sustained-release of pitavastatin from the nanoparticles was found. The blank PLGA nanoparticles had no effect on the viability of the endothelial progenitor cells in different concentrations. Compared with pitavastatin group, pitavastatin-loaded nanoparticles(0. 01 μmol/L, 0. 1 μmol/L)had more effects on the proliferation of endothelial progenitor cells. In conclusion, emulsion-solvent diffusion method is applicable in preparation of pitavastatin-loaded PLGA nanoparticles with good shape and sustained-release of interest. Pitavastatin-loaded nanoparticles could significantly improve proliferation of the endothelial progenitor cells.