In longwall mining, the instability of roadways can affect the mine safety, production rate and consequently the economic condition of mine. Therefore their stability analysis is one the most important technical problems in underground mining. The stability analysis and the design of support systems have to be investigated from two points of view; 1) the pressure and displacements of damaged zone around gate roadways due to the construction process and stress redistribution and 2) the working loading due to coal seam extraction and overburden caving that extends the damaged zone size. The aim of this research is the calculation of working effect on the damaged zone around gate roadway considering geomechincal properties of medium and the geometric characteristic of the roads and working. Therefore, a method has been obtained to calculate the total damaged zone area and working influence coefficient using geometric concepts and mathematical relations, then a design algorithm has been suggested based on the obtained method.