Nucleon and meson effective masses in the nonlinear relativistic mean-field theory introducing a nonlinear ω-ρ and σ coupling motivated by the quark-meson coupling model is explored. It is shown that, in contrast to the usual Walecka model, not only the effective nucleon mass m_eff,N but also the effective σ,ρ meson masses (m_eff,σ,m_eff,ρ) and the effective ω meson mass m_eff,ω are nucleon density dependent.