Abstract: Aphamosligma jarsuine on cuiguan pear was controlled by pirimicarb 50% ultrafine WP at 3000x dilution, in which three group treatments, I: spraying the aphicide at 3d before bagging, 25d and 48d after bagging; II: spraying the aphicide at 3d before bagging and 25d after bagging; III: praying the aphicide at 3d before bagging and 48d after bagging,were conducted. The results showed that treatment I was the best performance. This method was worth being extended.