This paper presents added mass, fluid damping and excitation (negative damping) coefficients for flow-induced vibrations of a shell-type long span gate in which the upstream gate face consists of vertical and inclined skin plates.The equations of motion of the shell-type long-span gate include integral fluid terms which describing the fluid motion in the resorvoir. The fluid terms were calculated for a periodic gate vibration, to reduce to a superposition of the acceleration and velocity terms, thus deriving the added mass, the fluid damping and excitation coefficients in the form of a series summation. The major characteristics of these significant parameters were calculated and examined.Additionaly a fundamental mechanism of the self-excited vibration was described.