Abstract: Processing the data of quiet day variation with methods of filtering and harmonic analysis eliminates parts of disturbances of high frequencies. So the regular patterns of seasonal average and statistical distributions obtained can reflect the characters of spatial distribution of S_q variations much better. Data processing shows that the maximum and minimum points of spatial distribution of Zcomponent of S_q variation are inconsistent with those of Hcomponent, especially in he winter. It needs further research. Besides, the amplitudes and phases of diurnal and semidiurnal harmonics for the quiet day variations also have seasonal variations and the first phases of both of them in summer always are greater.