Sex pheromone composition was analyzed for the oriental fruit moth(Grapholita molesta), and field trapping studies were also conducted to develop monitoring system with its sex pheromone in Korea. The calling and mating behavior of G. molesta were ween maximally 2 to 1 hr before lights-off and these behavior ceased after lights-off. Analysis of abdominal tip extracts from virgin females of G. molesta revealed 4 compounds, Z8-dodecenyl acetate (Z8-12:Ac), E8-dedecenyl acetate (E8-12:Ac), Z8-dodecenol (Z8-12:OH) and dodecanol (12:OH). In the field trappings, the best capturing activity for G. molesta was observed with the 95:5:1 blend of Z8-12:Ac, E8-12:Ac and Z8-12:OH but 12:OH showed no synergic effect. The most effective amount of sex pheromone blend was 0.5mg for a lure.