The function of mast cells in angioneogenesis is not completely known. Their role in the processes of the stimulation, inhibition and regulation of the angiogenesis is connected with mediators of angiogenesis produced by mast cells, e.g. heparin, histamin, bFGF, VEGF, chymase, tryptase and hydrolases. The enzymatical actions of mast cells on extracellular matrix, mostly by proteases, change its structure and facilitate creation of three-dimensional vascular system.