The electrical resistivity of CeBi single crystal has been measured in the temperature range 4.2-273 K and under pressure up to 18 kbar. The experimental results show that the Neel temperature increases with pressure and the magnetic resistivity ρs varies proportionally to InT at T>TN. By using Anderson model and taking into account p-f mixing mechanism, we calculated the pressure dependence of CeBi magnetic resistivity. The present results are compared with the experimental data. It is shown that the distance between the 4f level and the Fermi level decreases with rising pressure and pressure enhances the p-f interaction.