Some important topics in the IAG (International Association of Geodesy) Symposium held in July 2003, in Sapporo, Japan, such as the modernization of geodetic datum in China's neighboring countries, new strategy for the Earth gravity field determination from LEO satellites (One Step) and the new development in the GPS data processing techniques are briefly introduced in the paper. "International Terrestrial reference Frame”is taken as the global geodetic coordinate frame and its main problem is that the moving rates of all its frame points are supposed as a constant speed rate. However, this ITRF assumption is not true, which does not always coincide with practical situation. China's neighboring and near neighboring countries, like Japan, New Zealand, Mongolia, South Korea and Malaysia gave the introduction at the symposium about the geodetic datum modernization and geoid improvement work in their countries respectively. The Earth Gravity Field and its variation are usually determined with so called two-steps method. The so called one-step method, a new type of technique presented at the symposium to solve the same problem is an important development in this field. Some important advances in the field of GPS data processing are presented, such as the computational technique of coordinates and their movement for the continuous operation GPS stations from the GPS observational data with temporal correlation; the GPS data processing from the GPS observational data with systematic errors.