Planetary theory discusses the variation of the orbital elements of the solar system planets, through the theory of perturbation. Many theories were introduced to study this variation. The most powerful Hamiltonian mechanics procedures are adopted and explained clearly in this book. This book is recommended and directed to graduate students and researchers in dynamical astronomy and applied mathematics. The style is comprehensive and authoritative. We deal, with the construction of semi analytic Hamiltonian J - S planetary theory in terms of Poincaré canonical variables. The methods of work could be extended to be implemented, for the case of n planets (point masses), yielding more precise algebraic and numerical results, using the Jacobi - Radau system of origins, assuming any order in planetary masses. The terms of the Poisson series are truncated at power 6 at most in the eccentricity - inclination. The book includes the Macsyma programs used to obtain the expansion of the disturbing function up to order 6, in eccentricity - inclination, which is the upper limit of power for a personal computer. The expansion of -n took the space of 3400 pages in the site of internet.