Abstract: There are basic volcanic rocks with banded distribution in the Zhuazi-Liyuan-Labai township area of Northwest Yunnan Province.Previous views concerning the attribution of basic volcanic rocks are controversial.According to the investigation and research, the basic volcanic rocks are distributed in the westernmost margin of the Yangtze Block, mainly composed of olivine basalt, pyroxene basalt, volcanic breccia, et. The rocks have pillow structure and columnar joint, showing the eruption environment of water land interaction; the petrological geochemistry shows enriched alkali, low potassium, high titanium, enriched LREE, enriched LILE and enriched HFSE characteristics; the basic volcanic rocks in this area are generally similar to the Permian Emeishan basalt in Lijiang-Binchuan area of northwest Yunnan Province, and belong to the Emeishan basalt formation in Lijiang stratigraphic regionalization.In addition, a number of biological fossils were obtained from the bioclastic limestone intercalations in the middle and lower part of the basic volcanic rocks.The age is identified as Early—Middle Permian, which shows that the basic volcanic rocks were formed in the Early—Middle Permian.