Abstract: By adoption of the point charge model, and the use of the average covalent factor N as the fitting parameter and taking into account the spin-orbit interaction, at the same time using Bkq as the crystal field parameter, the absorption spectra of Cr3+:(NH4)2?C2O4?H2O single crystals were subjected to theoretical analysis and recognition by applying the ligand field theory complete diagonalization method and the absorption spectra of Cr3+:(NH4)2?C2O4?H2O single crystals were also interpreted in theory.