Four-section cut, a model similar to Swedish method, is an empirical method for blasting design in underground excavations. This method, often, has been used in excavating tunnels with cross section area of more than 10m2. Using the model for smaller tunnels needs some modifications to achieve proper quantity of the parameters. In this paper, four-section cut method has been modified for designing patterns for tunnels with cross section area of less than 10 m2. The applicability of the modified version has been examined through several blasting cycles and the ultimate optimized blasting pattern has been obtained. The previous blasting pattern of Razi coal mine, near Ramian city in Golestan Provience, has been replaced by the new pattern which was proved to be much more efficient.