This paper describes the influence of foundation rock properties(elastic modulus, Poisson's ratio) on the stress characteristics of the cross section of the fill dam gallery subjected to embankment load which has three shapes of the lateral side by using the finite element analysis. And the following results are obtained. (1) Tensile stresses at the top of the opening and the shoulder in the gallery decrease when Poisson's ratio of foundation rock is large. (2) Tensile stress at the shoulder and compressive stress at the contact area between the base plate and the side plate decrease when elastic modulus of foundation rock is large. (3) Itis desirable to select the gallery which has the steep slope of the lateral side to prevent the occurrence of crack.