This work envelopes differences of leaf characteristics among provenances of Fagus sylvatica. In addition to estimating the differences, we proceed to explain what influences these changes. Is the original genotype creating static normative morphology or are individual provenances responsive and plastic to the new environment? Phenotypic plasticity is well know topic in science but we are focusing on this problem from a different perspective. Comparison of provenances, which are planted in singular, relatively uniform place, brings new questions. In this paper, we measured variety of stomatal and leaf characteristics: stomatal density (SD), length of guard cell (LA), width of guard cell (WA), Stomatal Pore Index (SPI), leaf area (Sleaf), dry mass of leaf (mleaf), specific leaf area (SLA). We are evaluating data from two provenance sites located in Slovakia and Czech Republic. The relations between leaf parameters and climatic values of provenance origin places were examined. This provides essential insight how provenances respond in separated locations of distinct climates. The final idea is to assess phenotypic plasticity of individual provenances. We used Phenotypic Plasticity Index (PIv) and Relative Distance Plasticity Index (RDPI). Phenotypic plasticity is ubiquitous and generally regarded as a key mechanism for enabling organisms to survive in the face of environmental change. A lack of genetic variation can limit phenotypic evolution and evolution of plasticity. Plasticity itself may play a leading role in survival of European beech populations and sustainability of genetic diversity. Thus we should aim to create cohesive knowledge about provenances and they use in practical forestry.