The purpose of this paper is to investigate the soil-water characteristic curves for an unsaturated soil. To this ends, a series of suction measured test was conducted on the selected 4 kinds of soils taken from different sites of Korea, using modified pressure plate apparatus. Form the test results, the water contents, degree of saturation and volumetric water contents were analyzed with the suction. And the soil-water characteristic curves of unsaturated soil were drawn from the test results for various factors. The characteristic curves drawn with water content vs matric suction were classified certainly the difference in wet side but were not classified in dry side. The characteristic curves drawn with degree of saturation vs matric suction for unsaturated soil were shown the opposite inclination as compared with the former curve. But the characteristic curve with volumetric water content vs matric suction was described suitably not only in wet side condition but also in dry side. And it was found that the volumetric water contents of loose soil was high at the initial condition but that of dense soil was high at final condition (dry side).