Cancer, monogenic and cardiovascular diseases are the main targets of clinical gene therapy. For the most part, the research is making use of virus gene carriers based on genome of well characterized adenoviruses and retroviruses. There is an intensive research being done on cloning vectors that would successfully deliver the therapeutic genes into the cells of interest without causing side effects. Experimental research and first clinical trials emphasize therapeutic significance of recombinant adeno-associated viruses (AAV). The presence of AAV serotypes and possibility of their cloning in vitro allow conducting clinical trials of gene therapy using gene products introducing therapeutic genes into targeted cells, tissues, organs. In the work twelve known serotypes of AAV are described. The cell tropism as well as biological activity were discussed. Research shows that AAV vectors mostly are able to infect skeletal muscles (AAV1, 8, 9), heart (AAV9), liver (AAV8) and sense organs (AAV3, 4, 5).