The aim of the investigation was to study the possibilities of evaluating the biological properties of various tissue grafts analyzing autofluorescence level of their collagen fibers.Materials and Methods. The study involved various types of standard-produced tissue grafts, some of them being exposed to additional treatment to stimulate changes in collagen fiber structure. Analysis of preparations was made using light, fluorescent and confocal microscopy. To evaluate human cell adhesion on tissue grafts with different autofluorescence levels, M-22 human fibroblasts and human blood platelets were used.Results. Collagen autofluorescence has been registered in both fixed and non-fixed tissue graft samples, autofluorescence level of single fibers reflecting the extent of their compaction. Damage to the initial collagen structure leads to changes in tissue graft composition due to formation of picrinophilic fibers with very high autofluorescence levels, which do not appear in normal tissues or after collagen decondensation in conditions of hypotonia. Grafts with collagen fiber autofluorescence intensity 30 foot-candles are highly adhesive for M-22 human fibroblasts and donor platelets, whereas grafts with autofluorescence levels of more than 40 foot-candles exhibit significantly lower adhesive properties.Conclusion. Collagen autofluorescence analysis provides important data about connective tissue topography, intercellular matrix integrity and allows collagen defects to be revealed, even in non-fixed tissue slices and grafts.