Ostracode assemblages were surveyed at Lake Hamana, Shizuoka Prefecture, in 1996. Twenty-seven species among nineteen genera were discriminated from twenty-five bottom sediment samples. Ostracode individuals were poor in the north deeper region and rich in the south shallower region including the lake mouth. Ostracode assemblages were divided into three biofacies, e.i.A)brackish water inlet biofacies, B)inner bay biofacies, C) lake coast and lake mouth biofacies. Comparing with previous survey in 1970's, in biofacies C, minor compositional changes were recognized with increase of Aurila corniculata, appearance of Loxoconha hattorii and conspicuous decrease of Hemicytheruratricarinata.