Abstract: The coal seam is easily flow deformed under the conditions of complicated geological structure.Taking Yanshitai Colliery in Chongqing City as an example,by means of systematic observation of coal seam in the pit and through microscope,the macroscopic and microcosmic characteristics of coal seam rheology is analyzed,and its controlling factors,distributing rules and formative cause is summed up.The author of this paper pointed out that there exists obvious rheology of coal seam in Yanshitai Colliery.The control factor of rheology of coal seam included layer slip action,structure of coal seam,geologic position of coal seam and obliquity of coal seam.Because of these influence factors the strong sector of rheology chiefly concentrates in the flat stratum in No.4 coal seam,dense places of secondary geologic structure,as well as strong sector of layer slip structure.This conclusion has some guiding meaning to scientific evaluation and foreacsting of rheology of coal seam and the reasonable deployment of mining engineering.