This paper deals with the trend of the climatic change in South Korea during recent years, using the year-climatic method expressed by the Thornthwaite`s system(1948). The occurence ratios of each climatic type based on the moisture index, the potential evapotranspiration, the aridity index and the humidity one were computed. The occurrence ratios were obtained from the data presented by the 13 stations over South Korea during the period from 1906 to 1980, and the secular changes of the occurrence ratios of the year-climate types were examined. The results of this study are as follows: 1. According to the moisture index, the perhumid type(A) and the humid type (B<sub>4</sub>, B<sub></sub>, B<sub>2</sub>) are gradually increased, the humid type (B<sub>1</sub>), the moist subhumid type (C<sub>2</sub>) and the dry subhumid type (C<sub>1</sub>) show the decreasing tendency. Such a climatic trend makes South Korea humid, and is notable in the Middle region than the Southern region. 2. In case of the potential evapotranspiration, the mesothermal type (B’<sub>2</sub>) is mostly appeared in the whole country, the secular change of it shows the increasing tendency. 5o the warming phenomenon occurs all over the country. Because the Southern region is composed entirely of B` tpye, it maintains the balance in the secular change. The Middle region is lower than the Southern one in the occurrence ratio of B` type, but the increasing tendency of this climatic type keeps higher continuously. 3. When the aridity index and the humidity one were applied to South Korea, r type(little or no water deficit) forms the greater part of the whole country, and it appears gradually the increasing trend, w type (moderate winter deficit) which shows the increasing tendency occupies one-third of the whole country. For that reason, South Korea has no water deficit generally, but occasionally has a little water deficit in winter. 4. Uniting the moisture index, the potential evapotranspiration and the aridity index or the humidity one, the climatic types of Korea are 37 synthetic climatic ones. The 7 types which rank over 5 in the occurrence ratios of 5-year mean can be chosen among 37 types. The 5 types e.i. AB’₂r, B₃B’₂r, B₃B’₂w B₂B’₂r show the increasing trend, on the contrary, B₁B’₂w and C₂B’₂w show the decreasing tendency. Therefore, according to the secular change of the 7 synthetic climatic types, the climaic of South Korea has the warming and humidifing trend.