Abstract: Classical swine fever virus (CSFV) causes severe economic losses to the swine industry worldwide. To gain insight into the molecular epidemiology of classical swine fever in China, we analyzed a 190 bp N-terminal fragment of the E2 gene of 103 Chinese CSFV isolates. Clinical samples were collected between January 2008 and March 2011. CSFV was detected in 103 of these samples by RT-nested PCR and were selected for sequencing. Further analysis based on the E2 fragment sequences revealed that all of the Chinese isolates belonged to subgroups 1.1, 2.1 and 2.2. CSFV isolate of genogroup 3 was not found. The most significant observation between genetic and geographical distribution for the isolates in the study, especially for the subgroup 2.1 strains, was that they occupied the widest area since these viruses existed throughout mainland China. These results enhance our knowledge of the phylogenetic diversity of Chinese CSFV isolates and may contribute to the development of reliable diagnostic tests, epidemiological surveillance and effective strategies for disease control.