In 1970s, the generic bifurcation behavior of periodic orbits of Hamiltonian is fully discovered in some sense, by work of many mathematicians including Meyer and Schmidt. In this talk, the 8 types of generic bifurcation will be introduced. The ingredients, which is based on the analysis of 2-dimensional fixed points, will be introduced briefly. The talk is based on Meyer's 1970 paper and the book of Abraham and Marsden.