The D_st and SD variations of ionospheric total electron content (TEC) around equatorial anomaly crest region during SC geomagnetic storms have been statistically analyzed by using the continuous measurements of total electron content at Limping Observatory (25.00°N, 121.17°E geographic, 14.3°N, 191.3°E geomagnetic) from March 1977 to December 1993. The characteristic variations of D_st and SD of TEC are described and compared with the D_st and SD variations obtained from geomagnetic horizontal component recorded at Lumping Observatory. Some qualitative explanations are also attempted.