Johan Gunnar Andersson (1870-1960), a Swedish geologist，arrived in Beijing in 1914 as a mining adviser to the Chinese government. However, he was widely known in China as an archaeologist for his famous discovery of Yangshao culture. He stayed in China for more than ten years, and his career in China can be divided into three periods. First, he served as a mining adviser, and then he became a fossil collector. Finally, he did field work as an archaeologist and found many important historical sites in China. During his first years in China he played an important role in finding mineral resources and taking part in the activities of the Geological Survey of China. Based on his correspondence with European, American, and Chinese scholars, I will analyse his activities as a geologist and his contacts with Chinese geologists. In addition, I will describe how his researches were used by Chinese geologists, based on his Chinese geological work and journals such as the Bulletin of the Geological Society of China. Finally, I will discuss his archaeological work in Henan, Gansu and other regions and his influence on the study of ancient Chinese culture.