Abstract: Density function theory (DFT) method is difficult to treat strongly correlated system, while DFT + U produces U-dependent results. The electronic structures of two typical antiferromagnetic insulators CaMnO3 and LaMnO3 in perovskite manganese oxides were investigated by using the hybrid functional HSE, which combined the DFT exchange-correlation potential and the nonlocal Hartree-Fock exact exchange potential. The relationship among the energy gap nature, the valence states of Mn, the magnetic structure was discussed. The results showed that CaMnO3 is classified as charge-transfer insulator according to ZSA (Zaanen-Sawatzky-Allen) scheme. The energy gap of LaMnO3 shows anisotropic character, in which the Mott-Hubbard character is dominant along c axis and in spin-majority channel within ab plane, while the charge-transfer character is exhibited in spin-minority channel.