On behalf of the Organizing Committee, I would like to warmly welcome you to Xiamen, China, for the ICBB2013, the 4th International Conference on Biorefinery--towards Bioenergy on December 3-5, 2013. The conference will cover the latest development on various topics on bioenergy and advanced biorefinery technologies. In order to cope with the global energy crisis associated with rapid energy demand growths and to conserve and develop biological resources, the governments of all over the world as well as the academia and industries, have committed to the renewable and sustainable energy R&D, energy conservation and emission reduction, bio-inspired technology and biomass-based chemicals development over past decades. Exploitation of bioenergy and biorefinery technologies leads to the prospective pathway for ensuring the sustainable development of our society in the future. In this case, the American Institute of Chemical Engineers (AIChE) and the International Biorefinery Society (IBS) decide to hold the ICBB2013 in Xiamen, one of the most beautiful cities in China, which is the fastest growing economy in the present world. All scholars and experts in the fields of biorefinery, bioenergy, bioprocesses from the governments, academia and industries are invited to participate in this conference, a benign opportunity for our intensive academic exchanges. We sincerely hope this meeting will bring out new perspectives on bioenergy and biorefinery, and foster new ideas and collaborations for all the participants.