The process of the tapetal apoptosis is a key event in microsporogenesis. Previous studies have mainly focused on angiosperms, but ferns have not reported this aspect. The cytological features of the tapetal cells during apoptosis of Osmunda japonica was studied using transmission electron microscopy (TEM) and immunofluorescence technology. The main aim of this paper is to clarify the development type and apoptosis characteristics of tapetal cells of O. japonica. It provides a basis for the further study of tapetum cell apoptosis and spore development of ferns. The results showed that: (1) the structure of tapetum in Osmunda was of the mixed type. The outer layer of the tapetum was of the secretion type, and the inner layer of the tapetum was of plasmodium type. (2) The plasmodium tapetum underwent apoptosis during development. The cell wall and plasmalemma degenerated and the cytoplasm became dense and gradually vacuolated. The nuclei were collapsed and deformed. The chromatin condenses and small nucleoli were formed. The DAPI fluorescence staining became weak gradually. Organelles of mitochondria, plastids, endoplasmic reticulum, Golgi bodies gradually degenerated. The vacuoles contained fibrous, flocculent, dark osmiophilic granules and some small vesicles. Multi-vesicle bodies and multi-membrane bodies and apoptosis bodies occurred in the tapetal cells. (3) In contrast to seed plant, apoptosis of Osmunda started earlier than in seed plants; no nucleus apoptosis bodies occured during apoptosis. Besides sporopollenin, the tapetal cells also produced the fibrous, flocculent, dark osmiophilic granules during apoptosis. The materials were considered to form perispore of ferns.