The interaction between high intensity ultrashort laser and underdense plasma is numerically studied by using a particle in cell simulation. The results show that wake waves and Raman waves are excited in the plasma after the interaction between high intensity ultrashort laser and underdense plasma, the wavelength and frequency are conformed with theory. In the meantime under the action of waves, part of electrons in the plasma are accelerated to very high velocity, even near to the light velocity.