Variations in the percentage of materials coarser than 4.5 ϕ in sediment from Lake Biwa are closely related to global climatic change and are indicative of large fluctuations in sediment discharge into the lake. Coarse materials increased markedly during the interglacials (postglacial and last interglacial periods). The variations also are linked with solar insolation and have distinct periods of about 20,000 and 40,000 years which correspond to the periods of the obliquitical and precessional parameters. Periods of 60,000 and 120,000 years are major in the variations. ¿American Geophysical Union 1991