The joint roughness coefficient (JRC) is used to estimate the influence of the rock joint roughness on the shear strength. The traditional methods to evaluate the JRC are stylus and laser profilometers. The disadvantage of these traditional methods is that they cost much time or the cost of instrument is too high, and they are not suitable for a in-situ test. Therefore a simple three-dimensional digital image correlation (DIC) method is developed in this research to evaluate the JRC. In this research, a three-dimensional DIC method is proposed and only one camera is used. The results show that this method can be used to determine the three-dimensional coordinates of the joint surface and the measured JRC values are very close to that measured by laser profilometer.