The effect of different oxygen supply levels by controlling flask capacity on the performance of producing L-arginine using Corynebacterium crenatum SYPA5-5 was investigated in the batch fermentation process.The analysis of fermentation kinetic models and metabolic flux indicated that the hexose monophosphate (HMP) pathway was much more active to produce nicotinamide adenine dinucleotide phosphate (NADPH) for bacterial growth at a high oxygen supply level.L-arginine production was also enhanced at a high oxygen supply level because of high glucose consumption.On the other hand