Classical swine fever is important diseases affecting pigs. It results in great losses in their population and in limitations in the commercial international trade of pigs. The aim of the study was the preparation of the genetic vaccine against CSF and the estimation of its safety, protection value and immunogenicity. Clinical observations, body temperature and the immune response (haematological and FACS analyses) were monitored. Pigs vaccinated with the DNA vaccine were protected from the challenge, however, 2 days fever > 40 degrees C was registered. Slight activity of B and T cells was noted in those animals.