We report on our study of two-flavor full QCD on anisotropic lattices using O(a)-improved Wilson quarks coupled with a renormalization-group-improved glue. The bare gauge and quark anisotropies corresponding to the renormalized anisotropy ξ=as/at = 2 are determined as functions of β and κ, which cover the region of spatial lattice spacings a s ≈ 0.28-0.16 fm and mPS /mV ≈ 0.6-0.9. The calibrations of the bare anisotropies are performed with the Wilson loop and the meson dispersion relation at four lattice cutoffs and 5-6 quark masses. Using the calibration results we calculate the meson mass spectrum and the Sommer scale r0. We confirm that the values of r0 calculated for the calibration using pseudoscalar and vector meson energy momentum dispersion relations coincide in the continuum limit within errors. This work serves to lay the groundwork for studies of heavy quark systems and the thermodynamics of QCD including the extraction of the equation of state in the continuum limit using Wilson-type quark actions.