Sujishan gabbro rock body lies in the eastern Bogda Mountains as well as southwest of the Kalameili ophiolite belt , and covers an area of 1.8 km2. The lithology is of quartz-amphibole gabbro including higher amphibole (20%) and magnetite crystallization, which indicates original magma is water-rich and high oxygen fugacity . Its petrochemical feature shows that the magma belongs to the tholeiitic series. Rocks are enriched in LILE( Cs, Rb, Ba, Th, U) and remarkably depleted in Nb, Ta, Zr, Hf . The characteristics of petrography and petrochemistry indicate that the source of magma may be modified by subduction metasomatic fluids, as well, Sujishan intrusion body is the product of oceanic crust subduction. Zircon U-Pb age of Sujishan gabbro is 308.1±3.3Ma, earlier than the emplacement of alkali granite in the Kalameili ophiolite belt and being in accord with the rifting activity period, which indicates the Bogda rift underwent a conversion from the overall extension stage to the confined extension stage. On space, the Sujishan gabbro located in the direction of forward motion, where the paleo-Asian Ocean plate was subducting towards Junggar plate. On time, the Sujishan gabbro was formed during the active stage of rifting., Moreover, the lithogeochemistry confirmed some characteristics related with oceanic subduction. All of these facts suggested that the Bogda rift was designated as a subduction-torn-type rift resulted from the oblique subduction of the paleo-Asian Ocean plate towards the Junggar plate along the Kalameili subduction belt. The stress adjustion of Bogda rift from extensional mechanism to extensional-collisional transiton mechanism aroused the emplacement of Sujishan gabbro.