The First International Advisory Committees Review on CSNS took place May 1-3,2007 at the Institute of High Energy Physics (IHEP), Beijing, China. About 14 reviewers from USA, UK, Germany, Swiss, Japan, Korea and China, together with about 60 scientists and engineers from CSNS project, attended the review meeting. The International Advisory Committees consists of three sub-committees: Science & Technology Advisory Committee (STAC), Accelerator System Advisory Committee (ASAC), Experimental System Advisory Committee (ESAC). The committees reviewed the project goal, budget, schedule, and organization. During the meeting, 33 detailed presentations were given on all the CSNS sub-systems, involving system overview, technical design, challenges, R&D progress and system management. The reviewers gave CSNS some pieces of important advice and recommendation on the technical and management aspects. It is also a good chance to promote the international collaboration of CSNS.