Space weather refers to highly disturbed conditions on the sun, in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life and health. Adverse changes in the near-Earth space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of socioeconomic losses. This paper sources are believed to be on the sun. The propagation of these sources through the interplanetary space is reviewed. Finally, the interactions of the interplanetary disturbances with the earth¡¦s magnetosphere that include bow shock, magnetopause, magnetosphere, and ionosphere are considered. The example of the June 24-28, 1999 event is given to demonstrate the solar/interplanetary/magnetosphere inter-relationships. There is no doubt that the future COS-MIC project will be important for the study of adverse space weather.