Major fruit moths in commercial apple orchards are known as Carposina sasakii and Grapholita molesta. In addition, recently G. molesta is dominant species compared with C. sasakii in apple orcahrds. In case of Japan, the fruit damage occurred a lot unexpectedly in apple orchards of the northern Nagano during the harvesting season in 2004. As the result of identifying after emerging the larvae collected from the damaged fruit, Grapholita dimorpha was found out. The morphology of Grapholita dimorpha are almost similar to that of Grapholita molesta, and the shape of the damaged fruits was too similar to distinguish them. We installed sex pheromone traps of Grapholita dimorpha in apple orchards to check if there were Grapholita dimorpha in Korean apple orchards and to survey seasonal occurrence. As a result of survey by installing sex pheromone traps of G. dimorpha at one apple orchard in Uiseong-Gun and Gunwi-Gun area respectively, we could find high population density of G. dimorpha in sex pheromone traps. The peak of the first generation of G. dimorpha was dated in early May. The first generation occurrence of G. molesta in sex pheromone traps was lower than that of Grapholita molesta. However, it had higher occurrence of sex pheromone traps than G. molesta since it increased after mid and late July. Also, as a result of identifying in G. molesta traps, there were 673 G. molesta and 8 G. dimorpha. As a result of survey of 1,102 G. dimorpha in its sex pheromone traps, there were 1,099 G. dimorphaand 3 G. molesta.