Abstract: Objective: To explore the preparation of Gefitnib(PLGA) delayed-release microspheres based on Gefitnib for medol drug and PLGA for carrier.Methods: The microspheres were prepared using the O/W emulsification-solvents diffusion technique,the preparation technology was optimized by orthogonal design based on single factor experiment.The appearance of Gefitnib microsphere was observed by optical microscope and scanning electron microscope,the formation of PLGA microsphere was indentified by DSC,the release of Gefitnib PLGA microsphere was observed in vitro.Results: The results of DSC showed that the intermolecular force of Gefitnib and PLGA changed,Gefitnib evenly dispersed in carrier in the form of molecular.Gefitnib PLGA microsphere was white and smooth sphere,the mean particle size,encapsulate efficiency and drug loading of which were(10.35±0.32)μm,(88.44±1.26)% and(10.00±0.23)%,respectively.The release behavior of Gefitnib PLGA microsphere in vitro followed the zero order equation,Q=0.769t-1.800 9,r₂=0.980 8.Conclusions: The preparation technique of Gefitnib PLGA microsphere is stable,the release of drug in vitro of which is more than 5 d,and it has obvious sustained release effect.