Deep geological repositories are often considered for the disposal of high-level radioactive waste (HLW). HLW should be disposed of safely and permanently using two barrier systems: engineered barrier systems (EBS) and natural barrier systems (NBS). An EBS is an artificially suggested concept composed of various components. The buffer is one of the most important components since it plays crucial roles in terms of the safety of the entire disposal system, and compacted bentonite is considered a highly adequate buffer candidate material. As groundwater flows into the rock-mass and buffer, the degree of saturation of compacted bentonite increases. A soil-water characteristic curve (SWCC) represents saturation behavior, and thus it is essential to investigate SWCCs of compacted bentonite. For this reason, this paper conducted SWCC tests of Korean compacted bentonites according to dry density variations, as the dry density of compacted bentonite also varies in actual repository environments. The van-Genuchten fitting parameters (α, n) were obtained; α decreased in exponential form and n increased linearly according to dry density. Furthermore, using the obtained SWCC datasets, a simple empirical model was suggested to estimate the van-Genuchten fitting parameters. The mean relative error between the test results and the empirical model was approximately 8.6%.