For the determination/confirmation of the vector species of Japanese encephalitis in Korea and for the study of their bionomics, a preliminary assessment of different collecting methods of sampling mosquito population was undertaken. Man-biting catches, cow-biting catches, pig-baited window-trap hut, light trap, dry ice trap and man-baited double net were employed. The advnntages and disadvantages of these methods are discussed. A pig-baited window-trap hut and cow-biting catches outdoors are considered the best ways of collecting large numbers of Culex tritaeniorhynchus summorosus, the most important vector of Japanese encephalitis, for virus isolation and insecticide susceptility testing. The latter method requires, however, more man-power. Light traps set in a pigsty or cowshed are the simplest and most convenient tools for studying tne mosquito population density and seasonal prevalence.