Three new diterpenoids, 10-hydroxy-cembrene-5-one, 6-hydroxy-cembrene-5, 10-dione and 2 alpha,4 beta,15,16-tetrahydroxyl-dolabradane were isolated from the petroleum ether fraction of the alcoholic extract of Mallotus apelta Muell.Arg. Their structures were determined by spectral methods.