Abstract：The extension engineering method is combined with tunnel rock evaluation. In view of the variety and complexity of the factors influencing rock quality，the parameters reflecting the general rock engineering are taken into account for evaluation. On the basis of matter-element theory，extension set theory and dependent function calculation，a matter-element model calculating procedure is proposed. By practical calculation of the dependent degree to the quality classification of the tunnel rock，the Shibeiling tunnel rock is evaluated by extenics. Compared with the evaluation results by the former “RMR” method，the rock quality evaluation results obtained by the extenics method can more precisely reflect the engineering characteristics of tunnel rock.
