The symposium on photonic crystals and applications sponsored by Information Science Department,National Natural Science Foundation of China, was held on18 - 22 September2004in Tianjin,China.More than two hundreds and sixty scientists from55uni- versities and institutes have attended the symposium.The conference shows the important developments photonic crystal researches, including the base theories, the designs and preparations as well as the functional devices,etc.And the development plans for the fu- ture were also discussed.