This report is the result of the basic geologic investigation for the purpose of preparing the long-term development program of the U-jeon Consolidated Coal kline. The Consolidated Coal Mine is located at Gujeol-ri, Wangsan-myeon, Myeongju-gun, and Yucheon-ri, Bug-myeon, Jeongseon-gun, Gan-gweon Province (128$^{circ}$ 43′10.4"-128$^{circ}$ 46′10. 4"of east long-ititude, 37$^{circ}$ 30′-37$^{circ}$ 33′ of north latitude). This region, the western part of Taebaek mountain range, shows a ragged mountinous feature. Formations of the Pyeongan System of Paleozoic Era are distribu ted in the region with the surrounding Great Limestone Series of Joseon System which covers the south-eastern part of the region. The Pyeongan System is divided into four formations, namely, the Hongjeom, the Sadong, the Gobang and the Hongam, in ascending order. The sadong Formation intercalates several coal beds, and two coal beds out of them are minable. The coal beds are variable in thickness, having the repeated swelled or poket and the pinched parts, which suggest all intense disturbance caused by folding. The heat value of the coal is 5, 500cal. on the average. The total amount of coal reserves of the U-jeon consolidated Coal Mine is estimated at about thirty million metric tons.