Abstract: The mycorrhizal states of 256 species of pteridophytes which are naturally distributed in the tropi-cal and subtropical areas of Yunnan (Southwest China) were surveyed . It was found that the percentage of vesicular arbuscular mycotrophic associated with pteridophytes are lower than the angiospenns. The evolu-tionary trend offilicineae may be from rnvcotrophism to facultative mycotrophism, and at last to autotrophism.

Key words: Pteridophyte