Classical swine fever (CSF) is a contagious swine disease charactered by hemorrhagic fever and leukopenia,usually leading to substantial economic losses. To obtain a insight of leucopenia caused by CSFV infection, DNA microarray analyses of peripheral blood leucocytes (PBL) of the infected pigs was performed. Three health pigs were inoculated with a lethal dose of CSFV Shimen strain and their PBLs were isolated when the onset of typical clinical signs and then subjected to total RNA extraction followed by microarray analysis with Affymetrix Porcine Genome Array GeneChips. The results showed that the significant differences were observed in cellular apoptotic genes expression at 7 days post-infection (p. i.). The changes of the genes expression were confirmed by real time RT-PCR of some selected apoptosis-related genes. This study provided a valuable information for further investigating the molecular mechanism of apoptosis caused by CSFV infection.