Abstract: Objective To study the effect of levofloxacin sulphonate on HBV RNA of 3.5kb and 2.lkb in the 2.2.15 cell line.Methods HBV DNA,HBV RNA were examined by quantitative PCR;HBsAg and HBeAg were tested by radioimmunoassay.Results The quantity of HBV DNA,3.5kb HBV RNA and 2.1kb HBV RNA were 2.97pg/m1,0.40pg/ml and 0.27pg/ml respectively in the 2.2.15 cell line; 0.44pg/ml,0.20pg/ml and 0.13pg/ml respectively after treated by levofloxacin sulphonate(P<0.05 );the inhibited rate were 85.2%,50.0 0.6 and 48.1% respectively.The value of HBsAg and HBeAg were 42.1 and 36.0 respectively in the 2.2.15 cell superrant;6.0 and 16.2 respectively after treated by levofloxacin sulphonate,the inhibited rate were 85.7% and 55.6% respectively(P<0.05).Conclusion The effect of levofloxacin sulphonate against HBV infection may be through affecting the stability and translation of 3.5kb,2.1kb HBV RNA in the 2.2.15 cell line.