In population of Zuojiang Basin there are some charateristics:population increasing quickly, urban population taking small part, minority nationality population taking large part, labor resource being rich,most of them being physical labor and their intelligenee being little. In the present, to control general-adding ratio is the key for controlling population. In this paper, by calculating different figures of genreal-adding birth ratio, four forecast plans for development of population are made, the practical and ideal plan is chosen and the suggestions for realizing the plan of population are given.