A Purge & Trap Concentrator was used to analyze various volatile organic compounds(VOCs) in wat-er. The object of this study was to observe the purge efficiency of 40 VOCs in water according to the change of parameters (purge time drypurge time sample temperature) and to determine the optimum condition for VOCs using the purge & Trap concentrator interfaced with a narrow capillary connected to a gas chromatography/mass spectrometry. The optimum condition of purge and trap is as follows: purge time at 11min drypurge time at 5min sample temperature at 6$0^{circ}C$ at constant purge flow (40mol/min) constant desorption flow(20ml/min) desorption temperature(2$25^{circ}C$) and desorption time (1min) At this analytical condition the detection limits of VOCs was in the range of 0.1~0.5$mu$g/ml and the purge efficiency of each compound was over 70%.