The optical ground-based astrometry of solar system objects may have its accuracy strongly improved by using new methods for making observations and reductions of them. New photometric methods of observating the mutual phenomena occurring in the solar system, may provide astrometric data with a higher precision than the classical direct imaging. In order to help preparing observers for the future campaigns of observations (2008-2010) and to promote this kind of high-accuracy astrometry, we plan to organize a spring school in 2008 in Beijing, China, for PhD and post-doctoral students, and for interested young astronomers. © 2008 Copyright International Astronomical Union.