This paper examines variations in the geomagnetic total field recorded by eight stations in Taiwan from 1989 to 2001. A comparison of data from the international geomagnetic reference field (IGRF) and the eight stations shows that the annual change rates of the field reduce down to ± 5 nT/yr in 1997.9. Spatial and temporal analyses demonstrate that a zero isoporic zone (ZIZ) tends to lead to M ≥ 6.0 earthquakes within 2 years in the Taiwan area.