In addition to the known mulinolic and mulinenic acids, two diterpenoids, mulin-11-ene-13-,14--dihydroxy-20-oic and mulin-12-ene-14-one-20-oic acids, were isolated from the aerial parts of Mulinum spinosum (Cav.)Pers. (Apiaceae). Their structures were determined based on spectroscopic studies.