In 1918 Yabe described some Orthoceras chinese collected by Yamada from Chiu-tienya near the Szechuan-Kweichow border. But no date was given and the rocksfrom which the specimens came were not mentioned. In 1927 S. S. Yoh made areconnaissance sarvey from Chungking to Kweiyang. He found a shale consistingof Ordovician fossils at Shihtzepu 5 km. north of Tsunyi, Kweichow, but in Chi-kiang and Tungtzu such rock had not been discovered. V. K. Ting, T. K. Huang and Y. L. Wang while undertaking a study of thegeology along the proposed Szechuan-Kwangtung Railway, visited Szechuan andKweichow in 1929. They made a geological map of the Tungtzu area and clssifiedthe Ordovician rocks into a lower Loushankuan limestone, a middle Yangtienwoshale and an upper Chiehpei limestone Their result was however, not published,being given only in a paper read by Y. L. Wang at the weekly meetings of theNational Geological Survey of China. In the summer of 1939 the authors spent three months in studying the geologyof the Szechuan-Kweichow border. On account of other duties the senior author wascalled back In September, while the junior author stayed there until the end ofOctober. In the autumn of 1940 the junior author again went to Tsunyi, Kweichow andinvestigated the Shihtzepu shale. The region thus studied is situated along theSouthwestern Highway and extends from Kwanyinchiao in the southern part cfChikiang, Szechuan to Tsuyi, Kweichow. The sections exposed are ideal and coverrocks ranging from Cambrian to Cretaceous in age. Only the Ordovician formationsare treated in this paper. According to the authors. observations the Ordovician rocks of the Szechuan-Kweichow border can by separated into five groups. In ascending order they are theTungtzu formation, the Hunghuayuan limestone, the Malukou shale, the Neichia-shan formation and the Wufeng shale. A brief description of each is given below.