Abstract: The geomagnetically quiet daily variations S q field are analysed at Zhongshan Station,Antarctica during the period of maximum solar activities in 1991.The results show that:1) The geomagnetically quiet daily variations S q field are superposed more disturbances.S q field consits of both the S 0 q field and S p q field.2)S 0 q field are ratter regulervariations.Amplitudes of variation are larger in the sunlift ( Summer) polar region than in the dark (Winter) polar region.S 0 q(H) variation appears a twinpeak pattern in sunlift (Summer).S 0 q field are mainly controlled by the higher latitudinal ionospheric S q current system in the polar region.3)The morphology of S p q field variability have not difference both in the daytime and the nighttime.The intensity of S p q field variability is less in the winter than in the summer.Therefor S p q is largely depend upon both field aligned currents and ionospheric conductivity.4) S 0 q(Z) variation is larger than S 0 q(H) vatiation.In particular the amplitude of S 0 q (Z) is twice as larger as S 0 q(H) in winter.The geomagnetic quiet day data are also analysed at Beijing Ming Tombs geomagnetic observatory center of China in 1991.S q field variations caused by the S q current system at the mid low latitudinal ionosphere in the north hemisphere.