There are a lot of grottoes and earthen architecture sites located in northwest China. Over past 10 years, Chinese scholars have not only made a great deal of scientific researches and engineering practices on the conservation of ancient sites, but also cooperated with international organizations. The aim of the symposium is to demonstrate the latest advances and achievements in the field of international conservation of ancient sites, and also to provide a forum for the participants of this Symposium. The topics of this symposium are extensive, covering the new progress of conservation both domestic and overseas ancient sites. You will have opportunities to discuss the technologies and concepts about ancient sites conservation with experts coming from all over the world.