Tabanid flies were surveyed using New Jersey light traps and Mosquito Magnet traps at US Army installations and training sites in the northern part of Gyeonggi Province, Republic of Korea. A total of 344 tabanid flies, comprising 14 species and 5 genera, were collected from June to August during 2003-2004. Dominant species were Chrysops vanderwulpi $(57.3\%)$, Haematopota sinensis $(29.1\%)$, Haematopota koryoensis$(4.4\%)$ and Tabanus mandarinus$(2.3\%)$. Mosquito Magnet traps that generated $CO_2$ through the combustion of propane gas were nearly 6times more effective in collecting tabanid flies than New Jersey light traps. Based on Mosquito Magnet trap collections, peak populations occurred from mid-June to early July.