Increasing interest in converting bio-renewable chemical into liquid fuel, polymers and pharmaceutical products has attract extensive attention both in academic and industrial research to replace petrochemicals with novel platform chemicals derived from bio-based feedstock. Chemistry involving C4 chemicals (molecules with four carbon atoms) has been studied to make a variety of products, including fuel additives and polymer building blocks. This chapter gives an overview of the catalytic synthesis of C4 products from bio-sustainable chemicals, including C4 diols, alkenes, ketones and alcohols, by reviewing the impact of catalyst composition on product selective and the speculated catalytic reaction mechanisms.