Combined with field observation, well and seismic data, salt structures in Baicheng sag, Kuqa fold-and-thrust belt were constrained, and their formation mechanisms were investigated. Based on the investigations and previous studies, the authors propose a model showing salt flow related to salt structures in Baicheng sag, Kuqa fold-and-thrust belt, and it suggests that differential sedimentary loading plays an important role in Kuqa fold-and-thrust belt: 1) under bulk shortening and differential sedimentary loading, salt flew out of depocenter in three-dimensional; and 2) salt flew dominantly along the direction of contraction (N-S) and also obviously along strike (E-W).