A glass system of composition [(50-x) B2O3- 25ZnO-25Na2O-xCr2O3], where (x = 0.0, 0.1, 0.3, 0.5 mol.%) was synthesized applying traditional melt quenching technique. The amorphous nature of the samples was proved using X-ray diffraction. The effect of Cr ion content and γ ray irradiation on the optical, ESR, and FTIR spectra were studied. The optical absorption spectra were carried out and a ligand field theory analysis was studied, utilizing the resulting data. Through the analysis, the crystal field energy (10Dq), Racah parameters (B and C), and nephelauxetic function (h) were calculated. The results reveal that a strong crystal field strength around chromium ions. The obtained ESR signals pointed to both Cr6+ and Cr3+ states are present in the host borate glass. FTIR spectra showed a minor variation in the intensities of some absorption peaks after radiation. It can be connected to either some limited changes in the bond angles or bond lengths within the borate glass matrix. The effect of the γ irradiation on the structural properties of prepared samples has no remarkable change, so the obtained samples are more stables against γ irradiation.