Abstract: From microorganism′s composition,growth and reproduction and so on it is elaborated that the nitrogen was the essential element to microorganism vital activity.Degumming experiment was carried out with the ammonium salt and the nitrate as the nitrogen additive.The result indicated that the different nitrogen element has the different influence on apocynum venetum degumming,the remnant pectin rate is 14.1% with ammonium salt as nitrogen additive,15% with the nitrate.It demonstrates that the impact on degumming of apocynum venetum is different with different nitrogen additive through using the half response equation.The experiment and theory all indicates that the effect of ammonium salt as the degumming nitrogen additive is better than the effect of nitrate as the degumming nitrogen additive.