Effects of the Hall conductivity (&sgr;2) on the ionospheric dynamo were examined. Simulations for the ionospheric dynamo by the (1,-2) mode tidal winds were made for the cases with and without &sgr;2. It was found that existence of &sgr;2 does not modify global morphology of the height-integrated ionospheric currents much, although it enhances the total currents measured by the intensity of the equivalent current vortex by 2.1 times and diminishes the total potential difference by 1.4 times. This can be understood by the extended Cowling mechanism in which &sgr;2 makes secondary polarization field and the field drives the Hall current which enhances the original Pedersen currents. It was also shown that the equatorial electrojet and an undulated latitudinal profile of the geomagnetic H field variation near the equatorial electrojet can be understood by the latitudinal variation of the extended Cowling effect. ¿ American Geophysical Union 1991