///The Cretaceous sedimentary rocks in Thailand, Lao PDR, and Vietnam consist of entirely non-marine facies. They are widespread in the northern, northeastern, southeastern and southern parts of Thailand; northern, central and southern parts of Lao PDR; and northeastern, northwestern, central and southern parts of Vietnam. On the basis of the stratigraphic sequences and fossil correlation, two assemblages of the trigoniodid bivalves, the indicators of the non-marine Cretaceous, have been recognized from the Khorat Plateau of the northeastern and the Peninsular Region of southern Thailand, and Savannakhet (Donghen) Basin of southern Lao PDR. By means of the correlation of the bivalve assemblages, together with the other fossils, including the palynomorphs and dinosaurs, the non-marine Cretaceous strata were dated and correlated from Berriasian Barremian to Late Cretaceous in northern and southern Thailand, southern Lao PDR central Vietnam, resulted in revealing the history of the non-marine Cretaceous basins in Southeast Asia.