Summary: A novel gout disease characterized by visceral urate deposition with high-mortality outbreaks in goslings in China since 2016 was caused by a novel goose astrovirus (GoAstV) and resulted in serious economic loss. However, the epidemiology and variation of GoAstV in goslings in southern China and its evolutionary history as well as the classification of GoAstV are unclear. In the present study, systematic molecular epidemiology and phylogenetic analyses of GoAstV were conducted to address these issues. Our results showed that GoAstV is widespread in goslings in southern China, and the genomes of six GoAstV strains were obtained. Two amino acid mutations (Y36H and E456D) were identified in capsid proteins in this study, which is the dominant antigen for GoAstV. In addition, GoAstV could be divided into two distinct clades, GoAstV-1 and GoAstV-2, and GoAstV-2 is responsible for gout outbreaks in goslings and could be classified into Avastrovirus 3 (AAstV-3), while GoAstV-1 belongs to Avastrovirus 1 (AAstV-1). Moreover, the emergences of GoAstV-2 in geese was estimated to have occurred at 2010.1, approximately 12 years ago, while GoAstV-1 emerged earlier than GoAstV-2 and was estimated to have emerged at 1985.4 based on Bayesian analysis. The mean evolutionary rate for GoAstV was also calculated to be approximately 1.42×10 ^-3 nucleotide substitutions per site per year. In conclusion, this study provides insight into the epidemiology of GoAstV in goslings in southern China and is helpful for understanding the origin and evolutionary history as well as the classification of GoAstV in geese.