The environmental vibrations, caused mainly due to train/road traffic, construction activities and factory operations, are being investigated, globally, for their prediction, control and mitigation, basically, to improve the quality of life and robust infrastructure in the modern high tech society. The School of Civil Engineering, Beijing Jiaotong University in China is honored to be the organizers of the 4th International Symposium on Environmental Vibration: Prediction, Monitoring and Evaluation (ISEV2009). This symposium, sequel to the first one held in Hangzhou, China in October 2003, the second one in Okayama, Japan in September 2005, and the third one in Taipei 2007, will provide an international forum to exchange the knowledge, ideas and experiences for pursuing research on prediction, control and mitigation of environmental vibrations. Those who are interested in the environmental vibrations are welcome to participate in this symposium.