An appropriately available correlation through a series of formulas derivation and reasonable simplifications was established using some hypotheses. Then a wide range of culture conditions such as gas flow rate , stirrer speed and volume of the liquid in the vessel were correlated with volumetric oxygen mass transfer coefficient and the correlation is determined as: k_La=KQ^xN^yV_L^-y/3.15. The correlation factors K, x, y for the 30 l bioreactors calculated by sodium sulfite oxidation method were 0.004, 0.525 and 1.685 respectively. The correlation proposed here could guide the scale-up of fermentation to obtain an optimized initial volume of fermentation broth from lab-scale to a new higher scale and could inspect intuitively to the relationship between k_La and the other three parameters.