Abstract: The Karamaili faulting belt is well-known in the Northern Xinjiang and Central Asian area, and it came into being after the closure of the Paleozoic ocean. It has been a hot-debated issue on the ancient subduction polarity of the zone as well as whether it's a suturing belt among different ancient plates. Based on our investigation and indoor research of previous literatures during the past 20 years, this paper has briefly stated major geological features of the belt and its adjacent region, and put forward to some new points that the ocean, precursor of the belt, with remark of Karamaili ophiolite belt was a back-arc basin, that the region south of the belt was part of passive margin of the basin, and that the oceanic lithospheric plate was subducted northwards in the period of closure of the basin. Finally, the constraints of the belt on the distortion of ancient tectonic as well as metallogenic framework of the East Junggar region and the reconstruction of Paleozoic ocean-continent framework of the Central Asian region are briefly discussed.