[en] The magnetic systems described by a two-spin-per-site Heisenberg-like Hamiltonian are investigated in detail. When there are two sub-spins in one site, the magnetic behaviour becomes more complicated than usual Heisenberg systems due to the internal spin fluctuation. Spontaneous magnetization with the variation of temperature is calculated. The quantitative phase diagrams are given for ferromagnetic and antiferromagnetic states and qualitative phase diagrams are shown for mixed states. The roles played by sub-spin quantum number values, four exchange parameters and single-ion anisotropy are studied. The research gives us a comprehensive understanding of the magnetic systems with internal spin fluctuation