Abstract: The pinnae of compound leaf of Cycas could produce and evolve from a single pinnae to dichotomous pinnae gradually. From the first dichotomous, the pinnae will grow up and develop bi_,tri_even to multidichotomously usually in different species or sometimes in the same species. The species of the last form could be one of the most advanced species of Cycas. Stangerioides with forked pinnae should be the most advanced species of Cycas.