The diurnal flight pattern of Platypus koryoensis (Murayama) was examined using sticky traps attached to the trunks of oak trees in central Korea in 2011. The flight activities of the beetle were estimated on the basis of 2-h interval trap catches from 05:00 to 17:00, between June 9 and July 21 (the peak flight period of the beetle). Peak flight time of the beetle ranged from 09:00 to 13:00, with variations due to the day surveyed and the facing slope. The flights began when the air temperature reached 16.7 °C, and the flights peaked when the air temperature was 23.6 °C. Flights were not observed during rainfall, suggesting that rainfall is one of the factors that influence beetle flight. The time of sunrise was not significantly correlated with the flight initiation time. The direction of flight along with the slope was changed bidirectional to unidirectional (movement from upslope to downslope) between 9:00 and 13:00.