Plant biomass is a sustainable resource for the generation of energy, materials and chemicals, serving as a promising alternative to reduce the uses of nonrenewable fossil resources. Lignins in secondary cell walls of plants hinder polysaccharide-oriented biorefinery processes, while at the same time, they are increasingly being considered as an abundant source for supplying aromatic chemicals. Thus, a lot of research efforts have been made to modify lignin content and composition to suit different purposes. On the other hand, plants also produce a diverse array of specialized metabolites, including flavonoids and stilbenoids that not only confer plant stress resistance but also provide health promoting and pharmaceutical effects when consumed. For manipulation of these metabolites, it is essential to understand how they are biosynthesized and regulated in plants. My research aims at identifying the missing enzymes and regulatory mechanisms for the biosynthesis of lignin, flavonoids and stilbenoids in plants, and bioengineering plants for improved biomass utility. Ultimately, it would contribute to reducing the reliance on the uses of fossil resources for the production of energy, materials and chemicals towards realization of a sustainable society.