According to the change of the hyaluric acid (HA) during fermentation process, the fermentation medium was diluted with different multiples. The hyaluric acid in the diluted fermentation medium was determined by different methods. The result showed that, the measurement of the Bitter-Muir way, the CTAB turbidity way and the CTAB way were influenced by the fermentation medium, in which the CTAB turbidity method was influenced significantly. Then the data were adjusted according to the influence, and the adjusted data could more really respond to the HA production.