According to the theory of nonlinear Rosen-Zener tunneling, we investigate the nonlinear Ramsey interference of Bose-Einstein condensate in a double-well potential with Gaussian pulse. Rich Ramsey fringes are shown by the numerical simulations. The influences on the fringes of the atom-atom interaction and the period of Gaussian pulse are discussed. We obtain the analytical expression for the fundamental frequency of Ramsey fringes by using Hamilton equation. The relation of the frequency to the interaction strength and the Gaussian-pulse period is found by analyzing the fringes through Fourier transformation. The numerical simulations are consistent with our theoretical predictions.