To study the coupling between the magnetosphere and the solar wind at high latitudes, the cosmic rays window (CRW) is defined. The area of the CRW is related to the solar wind-magnetospheric conditions, such as the z component of Interplanetary Magnetic Field, the solar wind dynamic pressure, AE index and Dst index. This result on the CRW may be used to help forecasting the variation of the cosmic rays during the geomagnetic storms.