To investigate the seasonal occurrence of the pine sawyer, Monochamus saltuarius, its emergence rate was observed in pine log and Korean white pine log conditions after the logs were cut to a regular size and placed in a netted cage. Numerical measurement was also conducted for sex ratios, fresh weight, body length and width, head width, and length of adult antennae. In the Korean white pine logs, the first day of emergence occurred on May 2, the day of peak emergence observed on May 29, and the last day of emergence was on June 10. In the pine logs, the first day of emergence occurred on May 7, the day of peak emergence was observed on May 22, and the last day of emergence was on May 30. The period of seasonal occurrence observed for the pine logs was shorter than that of Korean white pine logs. Sex ratios were 0.58; the average fresh weights of males (331) and females (379) were 0.21 g and 0.23 g; body lengths were 17.6 mm and 18.4 mm; body widths were 5.47 and 5.81 mm; head widths were 3.30 mm and 3.42 mm; and antennal lengths were 40.28 mm and 26.40 mm, respectively. The ratio of the length of the antenna to the body length was measured to be 2.0 in males and 1.4 in females.