Abstract: Minutely mean values of geomagnetic data from each 11 stations nearby100°E GMand 300°E GMmeridians respectively are used to analyze the detailedfeatures of magnetospheric disturbances during a magnetic storm on November 26,1994. It is shown by the evolutions of H- and z-components, that the variationso f both region 1 and region 2 field-aligned currents are very important processesin the magnet osphere-ionosp here coupling. The coupli ng effect s in t he auror al areaare distinct obviously from that in mid--and lowWelatitudes. And the influence degreefor stations along different meridians is neither the same. The disturbance energyfrom the magnetosphere and the shielding effect of the region 2 field--aligned currentmay cause an abrupt intensification of ionospheric currents, and an eastward fieldand current may appearg which could last for about half an hour, in mid-andlow-latitudes at night side. Meanwhile, ionospheric plasmas of the F-region will belifted by E×B drift effect, which then leads to a simultaneously enhancement of h'F(minimum vertual height for F-region) at many stations nearby a same meridian.