Organic-inorganic ceramics were manufactured from natural plant structures such like scots pine, cork tree, rough horsetaile, hazel-tree and bulrush by using sol – gel infiltration, pyrolysis and subsequent sintering. The cystal phases of synthesized samples depend on the composition of sols. The microstructural features of the natural structure after treatment with sols and pyrolysis were retained in the ceramic structure. It is very important to take into consideration the slow and uniform temperature raising velocities as during the process, remarkable changes of mass and dimensions take place. Researches of Scanning elecron microscopy show, that samples, which have been treated with sol and pyrolised under inert athmosphere, preserve typical singularity of structure. Especially into samples made of hazel-tree wood are typical stuctures of vickers. This kind of structure could be forme by rutile into locked framework. The highest density of samples obtained after pyrolysis is characteristic for pine (1,32946 g/cm3), while lowest densities are for samples obtained from bulrush (0,12972 g/cm3). The same relationship also is observable for these materials in untreated state. The samples of bulrush and rough horsetail absorb humidity best of all. That is explainable by the remarkable porosities of bulrush and rough horsetail in comparison with the pine wood.