Abstract: Through study on Petrology of the Late Triassic volcanic rocks from Chachaxiangka area,the volcanic rocks belong to Elashan Formation and are calc-alkaline series.Considering the tectonic setting of intra-continental orogenic environment,the Late Triassic volcanic rocks initially may form in the continental marginal environment.Researched area and even Elashan area produced a series of right rotary sliding fault zone because "A" type subduction.Affected by northwestern Right-lateral strike slip fault zone,rock pore increased and strongly heat flow activities appears coursing magma spray out surface along these fault zone.