Yongcheon and Dangcheomul Caves are located on Jeju Island, the southernmost part of Korea. The island is under the strong influence of East Asian monsoon climate. Even though the Yongcheon and Dangcheomul caves are typical lava tube caves which probably formed between 0.2~0.4 Ma ago, they contain numerous carbonate speleothems which is less than a few thousand years old. Presence of carbonate speleothems is the result of overlying carbonate sand dunes which were formed by the transport of carbonate sands onto the cave from nearby beaches. Three stalagmites (YC-1, YC-2 and DC-1) were collected in their growth position in 2005, 2008 and 2010, respectively. The ages of the stalagmites were determined by 210Pb dating, radiocarbon dating and U/Th dating and by counting growth laminae. Age dating revealed that the ages of stalagmites range from 300 years to 3,000 years. High resolution stable isotope analyses were carried out. The YC-1 clearly shows Dark Age Cold Period, Medieval Warm Period, Little Ice Age and Global Warming. The YC-2 supports the data by the YC-1 and shows that textural data coincide well with geochemical data. Also, the YC-2 shows well defined transitional steps from Little Ice Age to present-day Global Warming Period. This study suggests that textural characteristics of speleothems can be used as a proxy to reconstruct paleoclimatic variations in addition to geochemical proxies. This research also clearly shows that carbon isotopic values of speleothems are more useful to understand paleoclimatic variations than oxygen values in the Jeju case.