To find out the affection of the sampling techniques to the result of a faunistic study, we surveyed the insect fauna of the Chungbuk National University (four different sites) for a year, from spring to fall. For each site, four different collecting methods: light trap, net sweeping, pitfall trap, and window trap, were applied and the collecting was done every other week for a total of 16 times. A total of 14 orders and 672 species were collected. 501 species were collected by the light trap, which covers about 75% of the total number of species, turn out to be the most effective, while other methods could only cover 18% or less. On average, only about 30% of the species collected at a given time of collecting were re-collected at the next collecting, which means about 70% of the species collected from the first collecting remains not collected in the next collecting if you collect insects every other week. The result suggests that, in addition to applying diverse collecting methods, frequent sampling, or narrow sample window, is another very important factor for a good representation of species diversity in an insect faunistic study.