Abstract: The stope stability analysis of test stope in the gently inclined ore body with medium thickness was carried out in the Jiaojia Gold Mine， Shandong Province. By means of the engineering geologic investigation and rock mechanics experiments at the -390m level， many mechanical indexes which reflect the quality of engineering rock mass were acquired. On the basis of the mass data analysis， applying of “Q” and “RMR” rock mass quality classification， rock mass rating model was established. According to the rock mass rating model， together the revised Mathews stability graph and the critical span design method， maximum exposed surface size of stope and maximum span were obtained. Through this great amount of analysis， it will guarantee the stability of stope when the span of stoping drift is less than 8m. The result was applied to the industry test， there the exposed surface size is designed as 75m×15m， and the insitu observation is used to monitor the mining process. The monitoring indicated that the caving and spalling of roof or sidewall do not occurred during the mining，and the stability of stoping drift is guaranteed.

Key words: Mathews stability graph, stability of stope, rock mass classification, span of stoping drift, critical span method