Objective To prepare proanthocyanidins/bletilla striata polysaccharide/chitosan microspheres ( PC/BSP/CTS ) and the physic-chemical characterizations were investigated.Methods The PC/BSP/CTS microspheres were prepared by spray drying method.The morphology of PC/BSP/CTS microspheres was observed by Scanning Electron Microscopy(SEM), and its physic-chemical characteristics such as diameters, release in vitro, moisture content, swelling ratio, solid density were studied.ResuIts The PC/BSP/CTS microspheres were successfully prepared by spray drying method, SEM showed that PC/BSP/CTS microspheres had the spherical shape with smooth surfaces.The diameters of microsphere A, B and C were 10~20, 2~15, 10~25μm.The in-vitro release showed that the cumulative release of three kinds of microspheres A, B, C was 25.07 %, 38.83 %and 60.00 % in 24 h, which had no burst release, while with time prolonged to 48 h, the cumulative release was 28.89%, 43.17% and 72.86%, respectively.The results of moisture content, swelling ratio, solid density were 15.35% ~23.51%, 46.50% ~105.80%, 0.375 ~0.496. ConcIusion The PC/BSP/CTS microspheres are successfully prepared by spray drying method which possess good characteristics and sustained-release effect, which would be as a good pulmonary drug delivery system.