Abstract：On the basis of elastic wave velocities recorded on the walls of adits and between adits by penetration method，the spatial distribution characteristics of wave velocities of rockmass in Xiaoguanyin dam site on the Yellow River are analyzed. It is shown that elastic wave of this area is related to in-situ stress field whose main component is gravity. The relationship between wave velocity and mechanical parameters of rock mass is established. By the means of elastic wave velocities，the relationship between mechanical parameters and earth stress field is established. By means of these results，it is feasible and easy to obtain or estimate reasonable mechanical parameters that are necessary for evaluation，calculation and analysis in those places where field test is not easy to be carried out.
