The Ionospheric Total Electron Content (TEC) data measured simultaneously by analyzing dual-frequency signals of the Global Position System (GPS) in two northern Nigeria equatorial stations: Ahmadu Bello University Zaria (ABUZ) with geographic latitude (11.16° N) and Longitude(7.65° E) and Birnin Kebbi Polytechnic (BKFP) with geographic latitude(12.46° N) and Longitude(4.20°E) during the year 2012 (R z =57.58) was used to study the diurnal, monthly and seasonal variation of equatorial ionosphere. The result shows that the mean TEC varies from a minimum at 0600 hrs LT to a peak value at about 1500 to 1700 hrs LT and then decreases. The seasonal variation in TEC maximizes during the equinox months followed by winter and is minimum during the summer months.