Investigations for conservation in liquid nitrogen of tospoviruses under the guise of infected leaf material and plant sap were performed. The protecting action of four cryoprotecting media was investigated . For reading the results an indicator test and ELISA were used. It had been registered that the specific biological properties and the virulent ability were fully preserved in the tospoviruses conserved with 10% dimethylsulphoxid and kept during three years in liquid nitrogen.