Increasing Lepidopteran pests such as Helicoverpa armigera are emerging pests of corn in Korea. They cause huge yield losses and deteriorate the quality of corn crop. We monitored the four major lepidopteran pests in major highland corn growing areas of Korea by employing sex pheromone trap during 2012 to 2015 for understanding those population dynamics. Among these species, H. armigera was found to be the main pest based on the damage intensity (80 ~ 90% of total damage). Some effective insecticides were selected such as Indoxacarb etc. Optimal timing of spraying was estimated at around 70 days after planting (earing season) to control H. armigera. Additional, two species of parasitoids (Therion circumflexum and Ophioninae sp.) was identified from H. armigera. However, more extensive survey for natural enemies is needed to set the natural enemy based control program.