AbstractAccording to the principle of biodiversity conservation , the species diversity should be regarded as an important target of synthetical benefit of the shelter2forests. The authors analyzed the species abundance of tree layer and shrub layer of the shelter-forest using the model of the Weibull distribution , and calculated the species diversity for each layer by means of various formulas and compared with that of the deciduous broadleaved forests in North China. The results were as follows :(1) in the valley the species abundance relationship fitted with the Weibull distribution model , suggesting that those trees with the greatest number of individuals were only restricted in a few species and evenness indices was small ; (2) its richness indices , evenness indices and species diversity indices were higher than those of the deciduous broad2leaved forests.