With several methods such as analysis of detritus component ,analysis of heavy mineral component, dip log, and thickness of strata, the paper analyzes sedimentary source and paleocurrent direction of Jurassic, ChePaizi District, north-west edge of Junggar Basin. Analysis of detritus component indicates the overall progressing direction of sedimentary source, analysis of heavy mineral component makes the main passage of source clear, dip log data gives accurate paleocurrent direction in the place of each well with this kind of data, but each of these three methods has a disadvantage with low data covering rate and high variety of covering density in 2-demensional space. In contrast, isolate map of strata from seismic data can be used to give prediction of paleo-topography and paleocurrent direction in much large 2-demensional scale, but it is virtually an indirect predicting method with disadvantage of low accuracy in local place. Integrating the high covering faculty of indirect methods and the high local accuracy of direct methods, a much accurate prediction about paleocurrent direction is put forward in this paper, and based on which a sedimentary facies model of alluvial fan-braided river-river plain sedimentary system is constructed. The model shows that current of alluvial fan progresses in the direction of SEE along the short axle with steep slope for its current energy can keep only in short distance, by contraries, current energy of braided river has the ability of keeping in much long distance, its current progresses in the direction along the long axle with mild slope，namely SE or even SSE. The model is much beneficial to raising the accuracy of turning seismic facies to sedimentary facies.