Based on an investigation into productivity，soil water and soil nutrient content of croplands

artificial grasslands (Medicago sativa)and shrub forests (Caragana korshinskii )，and natural grasslands in the northern region of Shaanxi Province，the productivity differences among different vegetation types and territories are discussed comparatively，and the reasons for these differences are analyzed.The results show that the productivity of croplands(foxtail millet) was far better than that other plants or vegetation types

but roduction stability is relatively poor in these systems.Productivity in artificial grasslands，shrub forests and natural grasslands is lower than in croplands

productivition stability，community biodiversity index and soil nutrient content of natural grasslands are the best among the surveyed plants (or vegetation types).It is proposed that besides water，low soil nutrient content and short of reasonable running also limit plant productivity improvement.To evaluate the productivity and longterm adaptation of different plants to the environment and offer guidance to the construction of vegetation systems in the region

long-term research areas or provisional survey study spots should be founded.