Abstract: The Onocleaceae in North-eastern China includes two genera and each genus contains only one species i. e. Matteuccia struthiopteris (L.) Todaro and Onoclea sensibilis L. All stages oi the development of gametophytes in the two ferns have been studied and compared. by using the light, phasecontrast and scanning electronic microscopy. The spores of the two species are bilateral, and monolete with a prominent perine, 4nd bean-shaped in equatorial view and elliptical in polar view. The main differences between the development of gametophytes of the two species are as follows:Matteuccia struthiopteris On the perine of the spore, there are a lot of small or large pores visible under SEM. the pattern of spore germination seems to be of Tangential type. The germ filaments develop 2-4 cellslong, generally biseriate and branched. The prothallial development is of the Adiantum type. The prothalli are naked and large broad-round cordate, two wings spread-out strongly. The midrib is heavy, 14-15 cells thick in 3 months old prothalli. The spermatozoid is about 65u long and in 2.5 coils, with a large vesicular globule 28u in diameter usually seated on the side of the spermatozoid visible under phase contrast microscope. Onoclea sensibilis All pores on the perine of the spore are small andscattered, and among them there are small spinate and irregular ornamen-tations. The spore germination is of Centripetal type. The filaments are 3-9 cells long, uniseriate or biseriate. The prothallial development is ofthe Aspidium type. The prothalli are hairy and broad-round cordate, andits midrib is 7-10 cells thick in 3 months old prothalli.The spermatozoidis about 62u long, in 3-3.5 coils, with the vesicular globule 23u in diameter bebind it.