Abstract: OBJECTIVE To prolong the analgesic effect time of resveratrol(RES) through the loading of poly(lactic-co-glycolic acid)(PLGA) nanoparticles to improve the ability of removing the defects of quick clearance and short action time. METHODS PLGA@RES nanoparticles was synthesized by double emulsion solvent evaporation method, and free drug was removed by centrifugation after loading; the shape was investigated by transmission electron microscope; laser particle size analyzer were used to determine the particle size, Zeta potential and stability; the entrapment efficiency and drug loading were measured by HPLC; the drug release behavior was studied by dialysis method; pharmacodynamics was studied by the acetic acid-writhing test, the hot-plate test and the tail pain test. RESULTS The prepared PLGA@RES had uniform distribution and no agglomeration, the mean particle size was (210.90±1.76)nm and polymer dispersity index was 0.22±0.02, Zeta potential was (-21.81±0.75)mV; the entrapment efficiency and drug loading were (89.62±2.52)% and (9.15±0.73)%; compared with RES, burst release in vitro of PLGA@RES decreased and sustained release was more obviously; the results of pharmacodynamics experiment showed that the characteristics of fast PLGA@RES effect remained unchanged, and the analgesic effect time was significantly prolonged. CONCLUSION The PLGA@RES is a prospective drug delivery system for solving the shortcomings of rapid clearance and short action time of RES. After sustained release, PLGA@RES can exert a lasting analgesic effect.