Being the biggest gas filed of the continental exploration in our country, Kela 2 gas field settle a foundation that Tarim basin is being to the important base of gas energy of "west gas to east" in our country.The main reservoir of Kela 2 gas field is the sandstones of Cretaceous Bashijiqike formation and the lower of Paleogene Kumugeliemu group, and the dolostones of the lower of Paleogene Kumugeliemu group.Thickness of the sandstone reservoir is 220.3-285.2m. Its porosity changes from 1.1% to 22.4%，the average is 12.83%. Its permerbility changes from 0.004×10-3μm2 to 1770.1×10-3μm2, the average is 51.46×10-3μm2. Primary intergranular pors are the main reservoir space. By comparing the sedimentary facies of the cored well and field section, the third member of Bashijiqike formation in Kela 2 gas field is fan delta front depositional facies. The main microfacies include the distributary channel ,gravitite and coastal-shallow lake.The types of rocks are sandy conglomerates, conglomeratic sandstones and brown mudstones.The second member of Bashijiqike formation in Kela 2 gas field is braided delta front depositional facies.The main microfacies include braided channel, distributary mouth bar and interdistributary bay. The types of rocks are brown medium to fine litharenite interbeded thinner mudstones. The first member of Bashijiqike formation in Kela 2 gas field is braided delta plain depositional facies. The main microfacies include braided channel and interdistributary bay. The types of rocks are brown medium to fine litharenite. During Bashijiqike stage,with paleo-climate arrid and torrid, there developed many fan-shaped depositional systems along the north frontier. They are constituted of many braided channel delta plain, and not a only one braided channel delta plain. In Kela 2 gas field, Bashijiqike formation reservoir geometry occures a lot of braided channel arising one erosion after another. Microfacies of every member has steady extensive distribution. Sandbodys connect continuously each other, and muddy partition beds are thinner and not continuous. Being a suit of excellent gas reservoir, Bashijiqike formation reservoir are charactristics of great thickness, extensive distribution, more continuous, high porosity and permeability and a few barrier beds in the space.