Abstract: Objective The study was designed to analyze and understand the changing characteristic and epidemic trend of influenza in Shantou City．Methods From January to December in 2005，total 405 person-specimens of throat swab from influenza patients in the downtown area were sampled for isolation of influenza virus，in which 33 strains of influenza virus，including 23 strains of A(H3N2) and 10 strains of A(H2N2)，were obtained，and the isolation rate was 8.15％，and 100 person-specimens of serum from general people were taken for determination of antibodies of A(H1N1)，A(H3N2)，B(Victoria family)and B(Yamagata family)through micro hemagglutination inhibition (HI) test with virus added to diluted serum for combination of 66 min．Results The positive rates were respectively 35.oo％，73.00％，16.00％and 9.00％．The positive rate for H5N1 antibody level determination of 90 person-specimens of serum from professional groups of people was 0．Conclusion The people in Shantou City have not been infected by avian influenza virus，and the strain of A(H3N2) was the predominant in 2005．The immunity of people for influenza A(H1N1) and B viruses Is lOW．Which should be taken seriously．