徐霞客(1586—1641)是明代末年我国杰出的地理学家和旅行家。

The late professor Chu Co-ching, the founder of geographical science in China and initial sponsor of Acta Gcographica Sinica (formerly Journal of Geographical Society of China), has made great effort in elueiating scientific achievements of ancient Chinese Scholars. As early as 1942, pro’f. Chu wrote a paper on the historical backgro-und of Xuxiake’s time. This important paper stimulates a series of research on the contributions of this great scholar in geographical sciences.Xuxiake’s (1586-1641) contributions are many sided but the most important is, undoubtedly, on the study of karst. Karst forms, especially tropical karst, are beau-tifully developed in China. Fig. 1, drawn in 168 B. C., is the oldest map on tropical karst known in the world. Xuxiake had spent almost four years (1636-1640) travell-ing and exploring karst forms and caves in Hunan, Guangxi and Yunnan, the great karst country of China and perhaps, of the world.His contributions in karst study are:(1) Karst process He pointed out the significance of fluvial erosion and gravity process in the formation of karst landscape.(2) Tropical karst In his remarkable book "Travels", he described morpholog-ical forms of tropical karst in minute detail and accurately noted the geographical dis-tribution of tropical karst in Southwestern China. Written in 1639, his account on tropical karst is more than two hundred years earlier than the earliest account of tro-pical karst in Europe.(3) Speleology Xuxiake had not only explored more than one hundred karst caves, but also measured their dimensions by foot steps and eyes. Kesults of cave sur-vey of Qixingyan, Guilin, by prof. Zhou Ting-ru in 1953 proves the remarkable ac-curacy of Xuxiake’s account of that cave showing the brilliant ability and great care of Xu’s observation.As the above three fields are important topics in modern karstology, it is not ove-rstated to say that Xuxiake is a great pioneer of Karstology in the world.