Abstract: Huaxiaosaurus aigahtens Zhao, gen. & sp. nov. was a mild herbivorous dinosaur that lived in Zhucheng of Shandong Province in Late Mesozoic 100 Ma ago. The specimen of Huaxiaosaurus aigahtens 11.3m in height and 18.7m in length is a skeleton assembled by many parts collected from several individuals of the same species. It was the tallest individual among the ornithopods. It had short forelimbs and tough hind legs, and it is another new finding after the discovery of the giant Shandongosaurus and Zhuchengosaurus.