Major elements in terrestrial detritus in sediments collected from ODP Site 1144 in the South China Sea were reported in this paper. Ti normalized ratios of the major elements exhibit significant climate-controlling patterns. During interglacial periods, the Al/Ti, K/Ti and Mg/Ti ratios were higher than during glacial periods, while Na/Ti and Ca/Ti ratios were lower than those during glacial periods. Considering that this terrestrial detritus came mainly from weathering products in South China, such variations in major elements indicate that chemical weathering in South China was strong during interglacial periods. Enhanced chemical weathering might have had something to do with the more humid climate in interglacial periods compared to glacial periods, which agrees with pollen records in the sediment cores from the SCS. Such climate patterns indicate that summer monsoons were strengthened during interglacial periods, which brought more precipitation to South China and enhanced chemical weathering there.