The fixed angle dispersion relations near forward direction are applied to the derivation of the integral equations of s-wave and p-wave pion-nucleon scattering amplitudes. The equations involve the contribution of annihilation process, in which the main contribution comes from the two pions intermediate state. In order to examine the effect of ππ interaction on pion-nucleon scattering, the observed values of scattering phase shifts are substituted into the equations, and the numerical calculation is given. Using the experimental informations of the form factors of the electro-magnetic structure of nucleon, and taking the square resonance energy tr=20, we obtain the I=I=1ππ scattering resonance width parameter γ=0.1. This result is consistent with the experimental data of the all three low angular momentum partial wave amplitudes, but the resonance width is small compared with the observed value.