Abstract:A study on the anti-moid activity of BCM, cinnamaldehyde and clove oil, was made by means of ultrami-crostructural observation The tesults show that both cinnamaldehyde and clove oil have strong anti-mold activity,tthe former being even stronger) . while BCM works well only in cascs of Aspergillus, Penicillium and Trichederma.SMF. and TME have found out that cinnamaldehyde is ahle tn destroy the wall of fungal cells, the coagulate plasmaand dirssolve the cell organs.