In the mid-17th century, geography in China developed to a new turning point,In order to study geography Xu Xiake was engaged in the geographic investigation in the field throughout his life,His work marked this turning point.Through field investigation he wrote the "Xu Xiake,s Travels" which contained unprecedentedly 1 abundent geographic knowledge,Before Xu Xiake there were two Chinese geographers, Li Daoyuan who investigated in the field to make clear the whole country's river system and Shane who investigated in the field to collect data from Tai Hu's river system,Xu Xiake undertook the field work in order to study geography,Xu Xiake was the only man who described this current practice first.Through the investigation in the field Xu Xiake wrote his travels involving geology, geomorphology, hydrology, climatology, phylogeography, zoogeography, racial geography, economic geography, settlement geography and topo-nomy. In his works he established the rule of causation, connecting and application.Xu Xiake was a pioneer in modern Chinese geographer,"Xu Xiake's Travels" was the first record of investigation in the field in modern Chinese geography.