Abstract: The gametophytes developments of 21 fems are researched. They are Angiopteris fokiensis, Osmunda vachellii, Osmunda banksiifolia, Alsophila denticulate, Pteris excelsa, Pteris vittata, Asplenium wrightii, Blechnum orientale, etc. It suggests these:(1) The cluster analysis with UPGMA on the gametophytes characters of 21 fems indicates that the ferns which have close genetic relationship in QIN Ren-Chang classify system(1978) are resemble in gametophytes characters, But there are some exception cases. (2)The gametophytes development of different species has many similar features, but there are many different features, too. (3)Some characters of gametophytes are stable, which can be used as classify evidence.

Key words: ferns, gametophytes, development, cluster analysis