Xiaotian—Mozitan ductile shear zone is one of the most important shear zone in Dabie Orogen，which overprints upon grey gneiss of northern Dabieshan. Through the research about structural geometry，kinematics ，the author get the conclusion that：Xiaotian—Mozitan ductile shear zone shows characteristics of a pipe on geometry，and has a subhorizontal sinistral shear style on kinematics. Geothermobarometer and the type of recrystallization of the deformed mineral reveal that its deforming temperature is about 618.2℃，and the geological pressure about 0.7GPa which indicates a mid—lower crust settings. Above research lead to a implication that：a pipe like ductile layer with a northern boundary of Xiaotian—Mozitan shear zone covered upon Dabieshan and the materials among the mid—lower crust flowed laterally along the orogen during orogenic period.