To investigate the infection and replication of hepatitis B virus (HBV) in primary cultured human granulosa cells. Human granulosa cells were cultured with HBV-positive serum. Media were collected and assayed for HBsAg and HBeAg by ELISA, and HBV DNA by quantitative PCR. HBsAg and HBcAg were detected by immunocytochemistry in cultured cells. HBV DNA and RNA were extracted and amplified by nested PCR. Intracellular HBV DNA was localized by in situ hybridization. By co-cultivation of human GCs with HBV-positive serum, a system was established to study HBV infection and replication in GCs. HBsAg in medium could be detected from 4 to 96 h, and HBV DNA could be detected from 12 to 96 h after exposure. HBsAg and HBcAg showed positive signals by immunocytochemistry. A 206-bp fragment was amplified by nested PCR to detect HBV DNA and RNA in granulosa cells. HBV DNA was detected in GC nuclei by in situ hybridization. HBV can infect and replicate in human primary granulosa cells. This culture system could enable us to study infection of ova by HBV.