Abstract: In this paper, the influences oi the orientation of rock layers and penstocks and anisotropic characteristics of schistous rock mass on the stress and strain distribution of the penstock are discussed. The results indicate that these influences are very large. The most disadvantageous case occurs when the penstock is perpendicular to the direction of rock anisotropy plane, i.e.the angle between rock layer and penstock is 90? So this should be taken into consideration in engineering practice. Moreover, the non-uniform stress distribution depends not only on the ratio of elastic moduli of rock mass in two perpendicular directions but also on the values of these moduli, especially on the value of shear modulus, so the measurement of shear modulus should be of great importance to the engineering proiect.