Abstract: The encapsulated granule of the sex pheromone of Grapholitha molesta Busck was prepared by phase separating,using ethyl cellulose as shell material.The factors which affect the average diameter and encapsulating rate of encapsulated granule of sex pheromones of G.molesta,such as the varieties and quantities of emulsifier,the varieties and quantities of release controlling agent,the stir speeds,the content of organic phase,concentrate of PVA (polyvinyl alcohol) in water phase and the dropping speeds of organic phase,were studied.The results showed that encapsulated granule of sex pheromone of G.molesta can be prepared with high encapsulating rate using emulsifier 700# as emulsifier and methyl oleate,di-n-butylphthalate or n-dodecane as release controlling agent;the effects of stir speeds,the content of organic phase,concentrate of PVA in water phase and the dropping speed of organic phase are obvious on the average diameter and encapsulating rate of encapsulated granule.The results showed that the encapsulated granules of sex pheromone of G.molesta have a sustained-releasing time of more than 110 days indoor.