Abstract: Paclitaxel-loaded PLGA nanoparticles(PTX-PLGA NPs) was prepared by emulsion solvent evaporation method with the biodegradable materials-poly(lactic-co-glycolic acid)(PLGA) used as carrier materials. The best formulation and preparation conditions were optimized by orthogonal test, investigating the influence of the ratio of paclitaxel and PLGA, the amount of surfactant, the amount of dichloromethane(DCM) and shearing rate on the preparation of nanoparticles. The optimal preparation conditions for PTX-PLGA NPs were as follows:the ratio of paclitaxel and PLGA of 4:1, the amount of surfactant of 0.1%, the amount of dichloromethane of 4 mL and shearing rate of 16 000 r·min^-1. With optimization of the formulation and preparation conditions, the PTX-PLGA NPs are regularly spherical in shape with the mean size of (207.1±20.5) nm, and the ζ-potential of the NPs is about (-23.8±2.5) mV. The encapsulation efficiency was estimated to be 14.45%±0.04%, respectively. The size distribution of PTX-PLGA NPs frozen dry powder was sustained stable character in 12 h. The results indicate that PTX-PLGA NPs were successfully prepared by modified solvent evaporation method, which could provide the experimental basis for the development of a new anti-tumor sustained-release formulation.