Abstract: In order to study the plastic zone distribution features of the surrounding rocks after excavated, the article firstly analyzes stress distribution characteristics of the surrounding rock; on this basis, circular roadway for the elastic and plastic zone is derived based on the Mohr Coulomb strength criterion. The plastic zone in the surrounding rock of the mine roadway under the conditions of different side pressure，different stress，different cohesion and different friction angle was obtained with the theoretical calculation．The evolution of the plastic zone is summed up from plastic zone equation. The results show that when λ is 1, the plastic zone is circular; when λ is less than 1, the plastic zone range is large at roadway side, the plastic zone range is small at roadway top; when λ is more than 1, it is clean contrary; the rapid development of the plastic zone in the corner; with the increase of stress, the plastic zone increases; with the cohesion increases the plastic zone reduces; with the cohesion increases the plastic zone reduces.