In this paper, we will present the zero-temperature phase diagram of the two-dimensional extended t-J model studied by the variational Monte Carlo (VMC) method. The introduction of the next and third nearest neighbor hopping terms t' and t” breaks the symmetry of the phase diagram. For the electron doped systems (t' positive), the phase boundary of antiferromagnetism (AFM) is pushed to larger doping density, and the superconducting (SC) region is suppressed, which are consistent with the experimental phase diagram.