The conference on Quantum Optics and New Materials (IV) was held at the Beijing Computational Science Research Center (CSRC), January 26-29, 2011. More than 100 scholars and students from different countries attended the conference. At the opening ceremony, Prof. X.T. He reviewed the background and discussed future directions of this conference series, followed by Prof. H.Q. Lin, the director of CSRC, who gave a welcoming address and introduced the newly established center to the participants. The conference provided a forum to discuss many recent developments in quantum optics and new materials such as the interaction between light and materials, non-classical properties of radiation, quantum interference, meta-materials. The conference was a great success with three keynote speeches, 31 invited talks, 8 oral presentations and 13 poster presentations.