Projction dimension reduction and optimaztion of dimentional data about the distribution of Grapholitha funebrana in U.S.A plum orchard were done based on projection pursuit(PP) technology.The result showed that spatial distribution of Grapholitha funebrana and directions and direction-levels were closely related on U.S apricot and plum.The larvae of Grapholitha funebrana aggregated on the centre and external of U.S plum,with much more larvae on the east and north.The density of Grapholitha funebrana forecasted in directions and direction-levels showed that the forecast and reality were in high optimization.The errors due to variables could be reduced by projection pursuit technology.Besides,the estimate could be much more accurate when there were more variables;and the tiny gap could show a very high weight value.