Two isolates of a new classical swine fever virus (CSFV) subgenotype, 2.1c (HNLY-2011 and HNSD-2012), were recently isolated from pigs in Hunan Province, China. The most significant difference in the amino acid sequences of the polyproteins from subgenotypes 2.1a and 2.1b is an SPA → TPV amino acid substitution at positions 777 and 779 in the E2 protein.