N6-methyladenosine (m6A) is a post-transcriptional modification of RNA involved in transcript transport, degradation, translation, and splicing. We found that HBV RNA is modified by m6A predominantly in the coding region of HBx. The mutagenesis of methylation sites reduced the HBV mRNA and HBs protein levels. The suppression of m6A by an inhibitor or knockdown in primary hepatocytes decreased the viral RNA and HBs protein levels in the medium. These results suggest that the m6A modification of HBV RNA is needed for the efficient replication of HBV in hepatocytes.