specially of mercury and mars on a time-scale of several 109 yr (laskar 1996). the results of laskar's secular perturbation theory should be confirmed and investigated by fully numerical integrations.
in this paper we present preliminary results of six long-term numerical integrations on all nine planetary orbits， covering a span of several 109 yr， and of two other integrations covering a span of ± 5 x 1010 yr. the total elapsed time for all integrations is more than 5 yr， using several d