Abstract: Stumping sprout is an effective renewing way of Hippophae rhamniodes L.subsp. sinensis population,while its ecological mechanism is not clear.In this research,all individuals of the population at different succession stag were measured to study the mechanism by the theory of "spatial series substituting for time series" and "plots arranged with age", the biomass investment and distribution were used as indicators.The results showed that:① the biomass accumulation of the population and its modules was in accordance with the Logistic equation.The biomass accumulation of sprout population could be divided into slow stage, rapid stage and again slow stage,meanwhile among the modules,the investment and allocation of biomass was obvious different;② sprout renewing was achieved by the adjustment of biomass investment and allocation among modules,especially by the prepositional effect and leading effect of the biomass investment of the sprout;③ the biomass allocation of the modules aboveground and underground had supplementary effect,as the allocation aboveground was low when the biomass underground was high,so the population must establish a tradeoff between breed and growth during the stump renewing process.