In this work, the Hamiltonian of the two body problem with varying mass was developed in the extended phase space taking into consideration the periastron effects. The short period solution was obtained through constructing a second order canonical transformation using “Hori’s” method developed by “Kamel”. The elements of the transformation as well as the inverse transformation were obtained too. The final solution of the problem was derived using “Delva-Hanslmeier” method.