MT 51005 as a potent inhibitor of phospholipase C(PLC) was purified from the culture broth of a fungal strain No. 51005 isolated from soil. It was identified as a benzaldehyde d erivative, anguillosporal. by the physico-chemical properties and spectroscopic data. Anguillosporal showed the inhibitory activity against purified PLC with an $IC_{50};of;13{mu}g/ml$. And it also inhibited the formation of inositol phosphates($IP_t$) in platelet-derived growth factor(PDGF)-stimulated $NIH3T3{gamma}1$ cells with an $IC_{50};of;0.8{mu}g/ml$.