Abstract: The tests on effects of phenols and their derivatives were conducted on fungal .The relationship between chemicalstructure of phenolic compounds and their deriuatives on antifungal activity was analysed. These results showed that: (1)p-polyhydroxyphenolic and o-polyhydroxyphenolic derivatives had better antifungal effect than phenol while m-polyhydroxyphenolic had the least effect.(2) After one of hydroxyl group of pyrocatedchol and hydroquinone was substituted for carboxylgroup , they became greatly less effective against these fungal.(3)After P-hydroxy benzoic acid was esterified, it is antifungalefficiency was obviously increased,but salicylic acid had not the same effect .They showed the strongest inhibitory effect whenthe length of esterification alkyl reached 5～6 carbon atoms.When the number of the carbon atoms exceeded 7(c≥7) their antifungalefficiency were rather worse.P-hydroxy benzoic acids esters had better effect against the fungal than O-hydroxy benzoic acid esters.(4) After the ethylation of phenol and the antifungal effect was worse except M-polyhydroxy phenol.

Key words: phenolis, chemically modified compounds, chemical structure and effect, antifungal activity