In Yanbian area located at the intersection between the EW - trending Paleozoic tectonomagmatic belt and the NE-trending tectonomagmatic belt，two suites of moderate-high potassic calc-alkalinc volcanic-intrusive complexes were formed in Middle Jurassic-Early Cretaceous. Due to the influence of subduction of Farallon plate in the period of 180-70ma (Middle Jurassic)，two-stage melting of pytolite at the depth of 80-90 km and under the condition of 24-27×108 Pa and 1078℃-1230℃pioduced basaltic-ndesitic magma，which in turn formed a suite of REE-deficient and well-differentiated volcanic rocks through unceasing differentiation and evolution. In 160-195 ma of Late Jurassic, there occurred northeastward transcurrent movement of Farallon plate and，as a result，magmatic activities.wexe weak in this area. In 14 0-130 Ma of Early Cretaceous，low-angle subduetion of Izanagi plate toward Eurasian continent took place. At the depth of 85-95 km and under the condition of 25. 5-28. 5 ×I O8 Pa and 1117℃ -11380℃，basaltic-andesitic magma was formed，which in turn produced a suite of REE-high and poorly-differentiated volcanic rocks.