A moderately strong electron-phonon interaction is supposed to be the causes of paring. On the basis of (1) the observation that the local electron-phonon interaction is rather strong in experiment and (2) the quasi-two-dimensional feature of CuO2 plane in ceramic oxides, a two-dimensional bisoli-ton model is established. The soliton solution with topological stability is given. It is shown that the bisoliton moves always with a velocity less than that of sound and it is varied along different direc-tions, they do not emit phonons, i.e., they do not transform their kinetic energy into a thermal one. The absence of an isotopic effect is explained because the critical temperature is independent of the mass of crystal lattice cell.