In 1928 he worked for the Cenozoic Research Laboratory of the Geological Survey of China and took charge of excavations at the Peking Man Site at Zhoukoudian.

Yang's scientific work was instrumental in the creation of China's Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, which today houses one of the most important collections of fossil vertebrates in the world.

He supervised the collection of fossil remains of and research on dinosaurs in China from 1933 until the 1970s.

He presided over some of the most important fossil discoveries in history, such as those of the prosauropods Lufengosaurus and Yunnanosaurus, the ornithopod Tsintaosaurus, and the gigantic sauropod Mamenchisaurus, as well as China's first stegosaur, Chialingosaurus.

[2] Yang's cremated remains are interred behind the museum at the Zhoukoudian site alongside those of his colleagues, Pei Wenzhong and Jia Lanpo.