Abstract： Dashanpu of Zigong City in Sichuan Province is world-wide famous for its dinosaur fossils, particularly the concentrative burial of a large quantity of dinosaurs. The cause of their concentratrative burial remains a problem of much controversy. Based on an analysis of such characteristics of the strata in the Zigong Dinosaur Museum and its surrounding areas as the lithofacies, depositional environment, shape of sandstone, and deposition background, this paper deals with the taphonomic environment of dinosaur faunae in Dashanpu and the cause of their concentrative burial. The authors consider that dinosaur remains were buried in frontal river mouth sand bar of lacustrine delta after their depth due to an unknown cause and river transport of their bodies instead of being buried in situ after their death due to poisoning.