The 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies 2008 will be held in Chengdul from Nov. 19-21, 2008, in the famous historical city of Chengdu, China. Technologies of advanced optical manufacturing and testing become an important branch of optical sciences as well as an indispensable part of industrial manufacturing science. They are closely associated with technologies of information, bioscience, material and manufacturing process, integrated with optics, mechanics, computer, measurement and other new technologies. At present, they construct the important technical support of a nation, even a symbol of the comprehensive national strength. The symposium will review the big progress of the kind since the first conference held in Chengdu in 2000, carry out academic exchange and discuss the development trend, planning and so on in the workshops. The program committee and local organizing committee of the symposium sincerely invite you participate in the 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies. We believe that the ancient historical sceneries and multi-cultural components in China will be a pleasant and impressive memory for the symposium as well as a valuable opportunity for China. We are looking forward to meeting you in Chengdu.