It is our great pleasure to introduce the papers of the proceedings of the 9th - ternational Symposium on Spatial and Temporal Databases SSTD 2005. This year s symposium continues the tradition of being the premier forum for the presentation of research results and experience reports on leading edge issues of spatialandtemporaldatabasesystems, including data models, systems, appli- tions and theory. The mission of the symposium is to share innovative solutions that ful?ll the needs of novel applications and heterogeneous environments and identify new directions for future research and...