Based on the s-d model, where the concentration of the d sites is low enough, magnetism and transport properties are investigated for the dilute magnetic semiconductors. In case in which the Fermi level lies near the upper edge of the s band, ferromagnetism is realized when the site energy of the d state (E_d) is located around the edge of the s band. In this case, down spin states of the d band are expelled out of the s band, resulting in a formation of the gap in the down-spin band. This leads to a half-metallic character accompanied by the resonance enhancement of the ferromagnetic interaction. The resistivity has a residual value at T=0 as the effects both of random distribution of the localized spins and energy difference between the s and d states.
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