Abstract: Based on the 1:200 000 gravitational and magnetic anomalies, the 48 faults in Junggar basin including 7 of first class, 6 of second class and 35 of third class have been determined, by means of multi-processing and analyses. In particular, the fault F6 in EW orientation and the fault F1 in SN orientation have been determined by detailed data processing and combining with crystalline basement deposition feature of the basin. The study shows that Junggar basin can be classified into such three first tectonic regions as Region Ⅰ (southern part), Region Ⅱ (middle part) and Region Ⅲ (northern part). The Region Ⅱ can be further divided into 4 sub-regions, forming a four-phase pattern. The each phase can be also divided into several further secondary geotectonic units. The structure, density and magnetic intensity are different in each phase, composing some differences in time and space.

Key words: Junggar basin, basement geotectonic pattern, gravity and magnetic inversion, multi-scale filtration, magnetic intensity