目的探讨急、慢性乙型肝炎及与ＨＢＶ感染相关的肝硬变和肝癌患者血清ＨＢＶＤＮＡ的临床意义．方法应用ＰＣＲ技术检测不同ＨＢＶ感染２０５例，患者血清ＨＢＶＤＮＡ，并与正常人２０例作比较．结果ＨＢＶ感染患者２０５例血清ＨＢＶＤＮＡ阳性率为６９３％，慢性乙肝、乙肝后肝硬变和肝癌患者的阳性率分别为７６４％，７１９％和７００％，显著高于急性乙肝患者２１７％的阳性率（Ｐ＜００１）；ＨＢｅＡｇ（＋）患者血清ＨＢＶＤＮＡ阳性率为９３６％，显著高于ＨＢｅＡｇ（－）抗ＨＢｅ（＋）／（－）和ＨＢｓＡｇ（－）患者的阳性率（４５６％，２５０％和１２５％，Ｐ＜００１）；血清ＨＢＶＤＮＡ阳性和阴性两组患者的血清ＡＬＴ水平无明显差异（Ｐ＞００５）．结论血清中ＨＢＶＤＮＡ持续存在可能与乙型肝炎的慢性化有关，而与ＨＢＶ感染患者的肝损伤无明显关系 Objective To investigate the clinical significance of serum HBVDNA in patients with acute or chronic hepatitis B and cirrhosis and liver cancer associated with HBV infection. Methods PCR technique was used to detect serum HBVDNA in 205 patients with different HBV infection and compared with 20 normal individuals. Results The positive rate of serum HBV DNA in 205 patients with HBV infection was 693%. The positive rates of serum HBVDNA in patients with chronic hepatitis B, hepatitis B cirrhosis and liver cancer were 764%, 719% and 700%, respectively, which were significantly higher than The positive rate of HBVDNA in patients with acute hepatitis B was 217% (P <001). The positive rate of HBVDNA in patients with HBeAg was 936%, which was significantly higher than that of HBeAg (-) - HBe (+) / (- (456%, 250%, 125%, P <001). There was no significant difference in serum ALT levels between two groups of patients with HBVDNA positive and negative (P> 0  05). Conclusions The persistence of HBVDNA in serum may be related to the chronicity of hepatitis B, but not to the liver damage in patients with HBV infection