Basing on independent cut method of Hurst exponent, and by combining the difference function and producing random number function, ten typical curves of rock joints’ surface were obtained. According to the empirical formula proposed by Tse and Barton and the data points of ten typical curve of rock joints’ surface, of which the fractal dimensionDf(D) were calculated. Adopted the yard-stick method to measure their fractal dimension,the relationship between JRC value and D value was fitted, the fitting results showed that the fitting curve reflect well with the relation of JRC and D.