We compare the stimulated Raman scattering (SRS) performance of a-cut and c-cut YVO4 in a single-pass Raman experiment. The undoped YVO 4 crystal shows its good SRS capability in a quasi-transient field. The non-axial scattering angles of Raman radiation are also studied, and the result is in good agreement with the physical model based on the phase matching condition. High-order Raman Stokes and anti-Stokes lights with good beam quality are obtained by means of Raman amplification. Our experiments show that Raman amplification is a practical way to avoid unexpected nonlinear effects and to obtain new wavelength picosecond lasers.