Papers in this issue are collected from part of the presentations at the 12th National Space Physics Conference, held at Sanya, China, on November 9-15, 2007. Although this is a traditional domestic conference held once every two years, the conference is also open to space scientists all over the world. As a multi-disciplinary conference; its subjects are widely covered including Space Plasma Physics; Solar Corona and Solar Wind; Planetary and Earth's Magnetosphere, Ionosphere and Upper Atmosphere, Cosmic-Ray Physics; The Sun-Earth System Couplings; Space Sounding and Probing, Simulation and Modeling; Polar Aeronomy; Space Weather and its effects.
More than half of the papers in this issue deal with data analysis and investigations of Double Star Program (DSP), the orbits of the two satellites of DSP have been specially designed to complement the ESA Cluster mission by maximizing the time periods when both Cluster and Double Star are in the same magnetospheric regions, or connected magnetically with each other. The two missions together allow simultaneous observations of the Earth magnetosphere from six points in space in a three dimensional manner. The main progress of DSP is briefly summarized in this issue. Besides DSP, the topics in this issue are mainly focused on CME, Solar wind and magnetosphere. Authors of presentations are very active in the front of the field concerned like Z.X.LIU, S.T. WU, Y. KAMIDE, Z.Y. PU, W.Y.XU and C.WANG, Q.G ZONG etc. This issue will provide an opportunity for readers to know more about the Conference and some latest results of investigations on solar and magnetospheric physics.