We study the Dirichlet mixed problem for a class of parabolic equation with double non-power nonlinearities in cylindrical domain = (> 0) × Ω. By the Galerkin approximations method suggested by Mukminov F.Kh. for a parabolic equation with double nonlinearities we prove the existence of strong solutions in Sobolev-Orlicz space. The maximum principle as well as upper and lower estimates characterizing powerlike decay of solution as → ∞ in bounded and unbounded domains Ω ⊂ R are established.