Spin excited states in an asymmetric magnetic organic co-oligomer diode are investigated theoretically.The results demonstrate that the structural asymmetry of the co-oligomer is modulated by the spin excited states, which is embodied in the wave functions of the eigenstates as well as the spin density wave.By calculating the transport property, a robust spin-current rectification concomitant with a charge-current rectification is observed in all spin excited states.However, the current through the diode is suppressed distinctly by the spin excited states, while the rectification ratios may be reduced or enhanced depending on the bias and the excited spins.The intrinsic mechanism is analyzed from the spin-dependent transmission combined with the change of molecular eigenstates under biases.Finally, the temperature induced spin excitation is simulated.An obvious rectification behavior is still obtained even at room temperature.