Evaporites with a large thickness were formed widely in the southwestern Tarim Depression during early Paleocene period. The evaporites of the Aertashi Formation were the products of intermittent transgression environment. In this study，8 drilling holes were chosen to identify and compare sedimentary cycles of evaporites. Four secondary cycles of evaporites were found. The rhythms characteristics of every cycle vary alternatively from evaporites to marl rock and this change of sedimentary rhythm was closely related with four minor transgressive regressive events. The comparative results of the drilling holes are: The developmental condition of secondary sedimentary cycles of each drilling holes was different. 4 secondary cycles of evaporites were developed completely in the western basin，and it reduced to 3 stages in the region of Ks101 drilling hole. In the Markit Slope Belt， only two stages were be delineated，missing the first two stages of secondary sedimentary cycles.The same obvious differentiation embodies in the sedimentary cycles growth degree and the thickness of sedimentary. Analysis result shows that，with the eastern expansion trend of the evaporites sediments，the depocenter moved gradually from Wx1、Wb1 drilling holes in front of Xikunlun Mountain to Tc2 drilling hole in the Markit Slope Belt. Two main controlling mechanisms may be considered for the alternation of evaporites sediments: the shape of foreland basin basement and the transgressive regressive events. In the end，according to distribution and migration of evaporites deposition，combined with the drilling position，the phased distribution range of transgressive process occurred out in the sedimentary period of Aertashi Formation：the process of sea invasion moved from the front of Xikunlun Mountain to southeastern of the basin, and finally extended to the whole depression.