The existence of structural surface in rock mass often makes notable influence on rock mass quality. This paper analyzes the evident shortcoming of the traditional rock mass quality index; and based on the project geological survey of main mine side slope rock mass of Baiyunebo iron mine

the rock mass structural network graphics are drawn by using the Monte Carlo method and the multifractal spectrum of rock mass structural distribution and complexity is calculated and drgwn according to the standpoint of multifractal geometry. The qualitative evaluation and quantitative analysis for rock mass are made. The rock mass quality classification is also made based on multifractal spectrum.