Abstract: Taxol, a novel antitumor agent, is a terpenoid secondary product with ringed formula structure. However, the pathways of taxol biosynthesis were still undefined. In this paper, a simple aspect about its secondary metabolism in plants and microorganisms was given. Recent research advances on biosynthesis of the diterpenoid tricyclo carbon skeleton and side chain groups of taxol was reviewed. Lastly, the influential factors on synthesis metabolism of taxol were discussed.