| Hippophae rhamnoides L. ssp. sinensis has a positive role in ecological environment construction and regional economy development in arid and semi-arid area of Northern China,because it is a multiple purpose tree, and it can grow up to a thick forests from a single mother ramet by clonal growth. For this reason, a wide-ranging study is carried out for a long time, but its content focus on the silvicultural techniques and utilization developing. The study of dynamics of sprout population is not reported up to now. In order to provide scientific bases for the management of sprout forest and enrich the knowledge of plant population ecology, based on the measurement of all individuals of population at different succession stag, sprout population in Mu Us sand-land were analyzed with the methods of spatial series substituting for time series and plots arranged with age. The results showed that the population could restore its structure and quantity by root sprout and stump sprout after cutting.(1) The age and height class structure of sprout population characterized by a transformation from an increasing type in the early period starting from the initial cutting through a stable type to a declining type. In the process of population declining, the ratio of young individual rise again by gap regeneration with root and stump sprout. Therefore, the population structure between stable type and declining type with potential recovering capacity was formed, in which the ratio of young individual was higher than that of the declining type but lower than that of the stable type.(2) The density of sprout population increased with the population growth before 4-year-old, and then it tended to be decreasing. Finally, population density maintained at a established level because of gap regeneration by root sprout and stump sprout. And at the earlier stage of succession, the population had higher density, smaller ramets and more ramets with complex axis than that of the population at later stage of succession , which was not only favorable for population occupying its living space but also for making good use of environmental resources. At later stage of succession, the population had lower density, larger ramets and more ramets with single axis than that of the population at earlier stage of succession, which could increase the probability of survival and growth of ramets as well as maintaining the enduringness of the population. (3) The biomass accumulation of population and its modules increased by Logistic equation with increasing of population age. The biomass accumulation of sprout population could be divided into slow accumulation stage (before 5-year-old), rapid accumulation stage (from 5-year-old to 9-year-old) and approaching upper limit with slow increasing speed (after 9-year-old). And the underground biomass accumulation had a preposition effect, but the aboveground biomass accumulation had a delayed effect. And at the earlier stage of succession, the biomass allocation mainly invested in the growth and extending of sprout roots (spacer), which enhanced the capacity of clonal growth and occupying underground space. At the middle stage of succession, the biomass allocation mainly invested in the growth of trunk and branches, which was favorable for occupying aboveground space and the accumulation of biomass.(4) The mean height, mean basal diameter and mean crown width of sprout population increased by Logistic equation with the increasing of population age, and it was divided into slow increasing stage (before 4-year-old), rapid increasing stage (from 5-year-old to 9-year-old) and the stage of approaching upper limit with slow increasing speed (after 9-year-old). Meanwhile, the mean height, mean basal diameter and mean crown width of sprout population had a positive correlation.
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