In this study, the spatio-temporal variations and trends of frost events (total frost days, first/last frost date) in South Korea were investigated using RegCM4.0 simulation data based on two RCP(4.5, 8.5) scenarios. To evaluate the performance of RegCM4.0 for the current (1981-2010) frost events, the daily minimum temperature of 49 observation sites in South Korea were used. Generally, the RegCM4.0 reasonably simulated the spatial characteristics of frost events, but the first (last) frost date was simulated by about 6.6 (3.3) days earlier (later) than that of the observation. As the results, the simulated number of the total frost days was 10.8 days greater than that of the observation. In the mid- 21st century(2021-2050), the first(last) frost date was projected to be delayed (bring forwarded) by about 7.9(3.1) days in RCP4.5 and about 9.6(2.3) days in RCP8.5, respectively. And the first(last) frost date in the late 21st century(2071-2100) is projected to be delayed (bring forwarded) by about 14.5(15.0) days in RCP4.5 and about 22.2(23.5) days in RCP8.5, comparing to the current climate. These changes could induce a significant decrease of the number of total frost days by about 26.5(47.7) days in the late 21st century under RCP4.5(RCP8.5). And the interannual variability of frost events under RCP4.5(RCP8.5) was projected to be relatively higher(smaller) in the mid-21st century than in the late 21st. The results indicated that the extreme frost events is expected to increase in the mid-21st century under RCP4.5, while in the late 21st century under RCP8.5, comparing to the current climate.