Hepatitis delta virus (HDV) is a single-stranded circular RNA satellite virus. HDV requires the hepatitis B virus (HBV) envelope proteins for the dissemination of virus particles Thus, hepatitis delta infection occur only in hepatitis B surface antigen (HBsAg)-positive individuals. HDV is divided into 8 major genotypes: genotype I, distributed worldwide including the Middle East; genotype II, mainly in Asia; genotype III, in South America; genotype IV in Taiwan and the Okinawa islands; and genotypes V to VIII, in west and central Africa. Patients who have HBV-HDV co-infection may be more prone to severe acute disease, fulminant hepatitis, accelerated progression to cirrhosis and hepatocellular carcinoma (HCC) than those infected by HBV alone. Currently, it is believed that 15 million to 20 million people are infected with HDV; however, this estimation may have limited accuracy given the lack of systematic screening, the inability to identify HDV in immunocompromised patients, and the lack of HDV RNA testing, also, due to an accelerated progression to cirrhosis, resulting in a lower prevalence of the disease than might otherwise be expected. The epidemiology of HDV infection worldwide was obscure, the prevalence of infection remained uncertain and geographic information are incomplete because many countries do not report the prevalence of HDV. Mapping the epidemiology of the infection is highly required. In this review, we tried to provide the Seroprevalence and epidemiological Characters of Hepatitis Delta Virus among CHB Patients worldwide