Abstract: The new gigantic sauropod dinosaur Ruyangosaurus giganteus gen. et sp. nov. from the early Late Cretaceous Mangchuan Formation of Ruyang, Henan , China is described. It is characterized by a lower neural spine, lack of centroprezygapophyseal lamina, a large, irregularly triangular deep fossa on the lateral surface of the neural arch, the prezygodiapophyseal lamina oriented anteroposteriorly, and a robust tibia, some 127cm in length. The discovery of Ruyangosaurus indicates that a higher diversity of sauropod dinosaurs occurred during the early Late Cretaceous than previously thought.