The small-scale dynamic of moth populations in spring was examined in a coniferous forest of southwestern Korea. Moths were collected with one 22-watt light trap for 29 days in April 2007. A total of 450 individuals of 38 species in 5 families were collected. The most abundant species was an epiplemid moth, Epiplema plagifera. The relationship between these dominant moths and their host plants is briefly discussed. We also examined influence of weather factors on the number of species and individuals collected. Multiple regression analyses showed that the two-day temperature difference explained 18% of the variance in the number of species collected, while air and ground temperatures explained 51% of the variance in the log-transformed number of individuals collected. This suggests that temperature affects local population sizes in spring, but variables other than weather may also affect the diversity of local moth populations.