We investigate the second order gravitational waves induced by the primordial scalar and tensor perturbations during radiation-dominated era. The explicit expressions of the power spectra of the second order GWs are presented. We calculate the energy density spectra of the second order GWs for a monochromatic primordial power spectra. For large
the effects of the primordial tensor perturbation with tensor-to-scalar ratio
lead to an around increase of the
signal-to-noise ratio (SNR) for LISA observations.