We measured the resistivity of heavy fermion CePtSi2 under pressure. At ambient pressure, CePtSi2 shows an antiferromagnetic (AF) transition at 2 K and a Fermi liquid like T-2 dependence ill resistivity below 1.5 K. With increasing pressure, the AF phase and T-2 dependence are suppressed. Above 1.4 GPa, a T linear dependence and pressure-induced superconductivity were found with the maximum T-c = 0.14 K at 1.7 GPa. Above 2 GPa, the T-2 dependence recovers just above T-c.