Abstract: The spore germination and gametophyte development of 21 ferns are studied. It indicates that:①the development period of prothallium and young sporophyte of the same species is different due to seeding time of spores; ②the optimal temperatures of spores germination and gametophyte development of 21 ferns are about 15-24℃; ③the rate of spore germination of rare ferns is much lower than the ferns which occur large populations in nature; ④the treatment with GA₃ can accelerate the germination of the spores; ⑤the prothallium changes from large to small, green to yellow when young sporophyte comes out. The prothalliums of all 21 ferns die away after the appear of the 3rd leaf of sporophytes; ⑥shapes of the 1st and 2nd leaves of the young sporophyte are different from those emerged later; ⑦spores cultured in dark can not germinate; ⑧a prothallium can develop only one young sporophyte though it has many archegoniums, and the spore propagation with leaf mould substrate is an economical method.