Abstract: Trunk window traps baiting with plant volatile compounds from damaged Larix gmelinii (Rupr.) Rupr. branches were applied in L.gmelinii forests in Aershan area, Inner-Mongolia. The effects of phyto-attractant, sex pheromone and their combination were used to test the effect of phyto-attractant on gypsy moth and the interaction of phyto-attractant and sex pheromone. The experiment was carried out in nine forest stands covering young, middle-aged and mature forests. Traps were also used in five other forests to test the effective distance of phyto-attractant. The results showed that the phyto-attractant could not exceed the attractive level of the sex pheromone except when the population size of the gypsy moth is very large. The phyto-attractant had an obvious synergistic effect on the sex pheromone. Gypsy moths 90 m away from the traps could be attracted with an optimum distance around 70 m. All of the attracted moths were males, most of which are virginal or not fully mated. The plant volatile compound had an obvious effect in monitoring and controlling the gypsy moth as a phyto-attractant, but it can also be applied as an accessory ingredient of sex pheromone in the management of the moth. The results also supported that our phyto-attractant can be developed as a pesticide for gypsy moth.