Analysis of 154 strains isolated in Russia and CIS countries in 1989-1999 showed that influenza virus A(H3N2) caused epidemics and epidemic rises 8 times, circulating together with A(H1N1) and B viruses. Antigenic drift was revealed using polyclonal and monoclonal antibodies. Analysis of antigenic properties of the viruses in the population showed that strains isolated during the same year were usually variants of one or rarely two reference strains. A drop of isolation rate of A(H3N2) strains on chick embryos in recent years was associated with increase in these strains' sensitivity to MDCK culture. Differences in amino acid sequences of epidemic and reference strain hemagglutinins were detected. The number of positions in which the changes were detected varied from 6 to 16 in all antigenic sites: A, B, C, D. and E.