This work has been carried out applying similar methodologies to former parametric autoecological studies on Fagus sylvatica stands in other Spanish regions. The beechwood territory of Castilla y León (Spain) has been stratified in order to select 37 representative parcels for sampling. Several physiographic, climatic, edaphic and forestry parameters have been elaborated from the sampling data. The parameter analysis has allowed finding out the parametric values that def ine the central and marginal habitats for beechwood stands in Castilla y León. The multivariable statistical analysis has enabled us to build predictive models for forestry parameters in relation to the most signif icant environmental parameters. The results are an important basis to establish the ecological aptitude of a territory with a view to establishing stable Fagus sylvatica stands in Castilla y León.