Abstract: The effective approaches to prevent the preharvest fruit drop of Mantianhong Pear were studied in this experiment. The results of the experiment showed that before Mantianhong Pear ripened one month, 2,4-D spray at 10~30mg/L, GA3 spray at 50~200mg/L or NAA spray at 10~40mg/L all prevented the preharvest fruit drop of Mantianhong Pear remarkably. In different thickness disposals, 2,4-D and NAA spray at 20mg/L both had the best purpose, and the fruit-setting rates were increased by 13.7% and 16.8% respectively compared to that in the control. GA3 spray at 100mg/L had the best purpose, and the fruit-setting rate was increased by 14.8% compared to that in the control.