Abstract:By using Mel'nikov functions, for the Poincare bifurcation problems of quadratic Hamiltonian system under cubic perturbation with one center and the periodic regions, which has a parabola and an invariant straight line as it's bounding. the approximate system to show that there exist just two single limit cycles, or just one double-limit cycle, or just one single-limit cycle and one separatric cycle are given.