Abstract: The ultrastructure of immune cells and natural apoptotic cells in central immune organs of Gushi chickens were studied by using transmission electronic microscopy technology. The results showed that the ultrastructure of immune cells in thymus and bursa was different between 17dayembryo and 4week and 19week Gushi chickens. The natural apoptosis was found in central immune organs of Gushi chickens. The main changes of apoptotic cells appeared in nucleus. The proliferation of mitochondria happened in apoptotic cells. The chromatin were highly condensed. The Cshaped nucleus and crescent nucleus and petallike nucleus and circleshaped nucleus etc were observed. The apoptotic cells broke into many apoptotic bodies, which were phagocytosed by macrophages.