Based on systematic petrochendstry are explored the tectonic settings of volcanic rocks bordering Yunnan and Guangxi in age of Permian-Middle Triassic. The oceanic island basalt is represented by the Longhuai pillow lava, which is, originally Hawaii-type one in the Paleotethyan ocean, an allochthon in the Indosinian foreland fold-and-thrust belt. The andesitic-basalhc rocks from Yutang-Natang, Yanaiia Mts. and Fuhng River indicate the oceanic basin subducted, overall, from Perman right up to Middle Triassic, which reflects dishnct geodynamc background of the Paleotethyan evolution from that in southwest Yunnan. The knowledge provides new teshmonies for the area bordering China and Vieinarn being, tectonica1ly, Paleotethysides and key data for reconstructing Paleotethyan evolution there Based on systematic petrochendstry are explored the tectonic settings of volcanic rocks bordering Yunnan and Guangxi in age of Permian-Middle Triassic. The oceanic island basalt is represented by the Longhuai pillow lava, which is, originally owned Hawaii-type one in the Paleotethyan ocean, an allochthon in the Indosinian foreland fold-and-thrust belt. The andesitic-basalhc rocks from Yutang-Natang, Yanaiia Mts. and Fuhng River indicate the oceanic basin subducted, overall, from Perman right up to Middle Triassic, which reflects dishnct geodynamc background of the Paleotethyan evolution from that in southwest Yunnan. The knowledge provides new teshmonies for the area bordering China and Vieinarn being, tectonica1ly, Paleotethysides and key data for reconstructing Paleotethyan evolution there