Abstract: Jiangcang districtis located in the northeast of Qinghai.It is the biggest mineral area in Mulicoal field.After several years of geological work,we have collected abundant data on the structure characteristic and their control on the coal system.The structure of Jiangcang mineral area is north-steep south-slow dissymmetry syncline structure.It controls the extension of coal system and coal seam.There are three tectonic faults which are oriented east-west,northwest-southeast and northeast.The east-west faultis the main structure controlled coal system.Direction faultage penetrates the shallow portion of the south and north limbs of the syncline,That becomes the nature boundary of the south and north mining field.The coal strata is clearly controlled by tectonics.