Abstract: Effect of Cu2+ were studied ions on the growth morphology and citric acid production from blackstrap molasses by Aspergillus niger GCB-47. The addition of 0.02% CuSO4 to the fermentation medium reduced the Fe2+ ions conc. by counter-acting its deleterious effect on fungal growth. The Cu2+ ions also induced a loose-pelleted form of growth, reduced the biomass concentration and increased the volumetric productivity.