Wood plays a very important role in people's lives and has been used since ancient times as a building material and firewood. It is very important to know the micro and macrostructure of wood of different taxa, because it helps us to determine wood species/genera and it directly or indirectly affects wood’s physical and mechanical properties. A total of 29 commercially important wood species were investigated in this paper; 7 conifers and 22 deciduous species. For the purpose of this thesis a collection of wood blocks (xylarium) was made. It consists of 29 wooden blocks together with microscopic slides for each wood species, which were done in three characteristic sections. These collections are the first of their kind at the Department of Biology, Faculty of Science and will serve as a learning material and as a comparative collections for the determination of wood samples. Collections are also expected to be supplemented with new species in the future. The paper contains a photo documentation of all microscopic slides and wood blocks from xylarium. A detailed description of the anatomical and morphological structure of the wood has been written for each wood species, and it is evident that there are clear differences in the structure of conifers and deciduous trees, as well as among individual species/genera. The paper also contains a determination key, which can be used for identification of each species or genus studied in this paper.