  We present updated results of the CP-PACS calculation of the light hadron
spectrum in $N_{\rm f}=2$ full QCD. Simulations are made with an RG-improved
gauge action and a tadpole-improved clover quark action for sea quark masses
corresponding to $m_{\rm PS}/m_{\rm V} \approx 0.8$--0.6 and the lattice
spacing $a=0.22$--0.09 fm. A comparison of the full QCD spectrum with new
quenched results, obtained with the same improved action, shows clearly the
existence of sea quark effects in vector meson masses. Results for light quark
masses in $N_{\rm f}=2$ QCD are also presented.
