Objective:Aconitum brachypodum is an endangered species with a very small distributional area.To find out the possible cause of distributional limitedness，the population and reproductive biology were observed.Method:The environment of Aconitum brachypodum was observed，the developmental process from flower bud to f ruit was observed and discussed in this paper,and the pollination efficiency,the fertility,pollination insect and the plan of action pollination process was observed and discussed.Results:It was clear that the breeding behavior of Aconitum brachypodum belongs to cross-pollinate.The pollination insects are most bumblebees，the pollination efficiency and the fertility is very high,and the developing of the seed embryo is irregular.Conclusion: Population biology and the reproduction biology preliminary study of Aconitum brachypodum is all very important to its generation extension and even the evolution,so the consummation of this thesis provides the theory basis of protection and the direction of scientific cultivation and logical using.