In this study, the authors report the contents of TOC, opal and CaCO3 in sediments recovered from Core DGKS9604 (28°16.64’N, 127°01.43’E), with aim to understand the changing influx of terrigenous materials and paleo-environmental evolution of the middle Okinawa Trough during the last 28 ka. The authors selected 93 samples to measure the opal by colorimetric measurement of phosphorus as molybedenum blue and 188 samples to analyze total carbon, total organic carbon and carbonate. The changes of CaCO3 content and accumulation rate were contrary to the downcore variations of opal and TOC, showing lower values during the late last glaciations and gradual increase during the last deglaciation, which suggests the dilution effect induced by the terrigenous materials.