The first provenance trials of European beech in Serbia were established in spring of 2007 in the framework of COST Action E52: "Evaluation of Beech Genetic Resources for Sustainable Forestry". Trials are placed on two localities: Fruška Gora Mountain (northern part of Serbia) and Debeli Lug (eastern part of Serbia). In the previous years, several studies regarding variability and adaptability of different European beech provenances were conducted in these sites. In order to understand the complex effect of site characteristics on provenance performances, it was needed examination of environmental characteristics of given localities. Therefore, the aim of this study is detail, comparative analysis of: a) climate characteristics of sites, b) pedological characteristics of sites and c) degree of presence and cover value of weed flora. Annual and mean monthly values of major climate elements, significant for the development of vegetation are presented: mean temperature, sum of precipitations, pluviometric and hydric balance, climate-geographical characteristics – thermodrome coefficient after Kerner, Lang’s rain factor, pluviometric hazard and drought index after De Martonn. Climate type was determined using Thornthwaite-Mather and Lang’s method. Pedological characteristics are given throught the physical and chemical properties of soil. Phytocenological observations were performed using Braun-Blaquet method. Life form of plants was determined after Raunkiaer. Results revealed significant differences inenvironmental characteristics between sites Fruška Gora Mt and Debeli Lug, which could lead to different performances of provenances depending on site of planting.