The change of apoptosis and apoptotic regulatory gene Bcl-2 and Bax expression in pregnant rabbit placenta were investigated. Nuclear DNA fragmentation analysis indicated that DNA ladder, which is characteristic of apoptosis was detected in D18 and D26 pregnant rabbit placenta and the scan results showed that DNA fragmentation increased significantly in D18 and D26 pregnant rabbit placenta compared with that in D12 pregnant rabbit placenta. TUNEL test and immunolocalization of active caspase-3 demonstrated that apoptosis occurred in D12 pregnant rabbit placenta, and apoptotic cells localized predominantly in syncytiotrophoblast throughout pregnancy. Immunoblot analysis showed an increase of Bcl-2 and Bax expression throughout pregnancy, and the change of expression of these two proteins resulted in an increase in Bax to Bcl-2 ratio. The results demonstrated that apoptosis occurred in syncytiotrophoblast in rabbit pregnancy and apoptotic cell death increased from early to the end of gestation period, moreover Bax to Bcl-2 ratio may be related to apoptosis in placenta.