We study a mechanism of superconductivity in non-centrosymmetric systems like CePt3Si, where the spin-triplet superconducting state coexists with the spin-singlet one in principle, because of the lack of inversion symmetry. In the non-centrosymmetric system, anomalous spin fluctuations like spin fluctuation of off-diagonal spin indices also remain in addition to usual spin fluctuations. It is found that superconductivity appears around the magnetic phase, where the usual spin fluctuations induce spin-singlet superconductivity, while the anomalous spin fluctuations make spin-triplet one develop to stabilize the superconducting state.