Bioglasses and bioactive glass-ceramics used in medicine and dentistry as bone substitutes have unique properties; they are able to joint with living tissues by hyroxyapatite surface layers as well as to stimulate tissues to regeneration. Lately a special attention was given to the new generation of these biomaterials (glasses and glass-ceramics) produced by the sol-gel method. Gel-derived biomaterials are characterised by higher bioactivity, especially concerning their effect on the faster reconstruction of living tissues. Gel-derived materials of various chemical and phase compositions were obtained in laboratory conditions in the form of powders, compact and porous sinters as well as in the form of coatings on inert base. The simulated body fluid (SBF) test and biological "in vitro" tests were carried out for gel-derived biomaterials using as a control bioglasses produced by traditional melting way. Moreover, "in vivo" examinations were conducted. In these experiments gel-derived bioglasses in the form of 100-800 μm granules were implanted to the deffect in rabbit shank bone. Heterograf made of alien bone tissue was used as a control material. The progression of bone reconstruction was estimated on the basis of radiological tests, scanning micrtoscopy (SEM) and EDAX analysis, structural examinations of fillers (FTIR, XRD) and histopatological tests. It has been found that the process of reconstruction of bone tissue proceeds faster in the presence of gel-derived bioglass in comparison with its when heterograft was used. Results of our experiments indicate the high bioactivite of gel-derived biomaterials.