Orange fruit is a Thai popular consumers in general. And can be exported to sell abroad each year tens of millions of baht. But the orange plant in Thailand have yield decreased. Due to the environment and manufacturers.The yield and the orange tree dead is an important problem at present, which mainly caused by fungal infections, such as sugar, which have caused the disease caused by the fungus, Septobasidium Sp.This sugar mold spores dispersed by fiber and often found this infection on the oranges in the rainy season. The research shows that the tannin is effective in inhibition of Septobasidium sp., which can be found in the tannin is effective as a precursor in the reaction Brown related enzyme activity of fruit and as preservatives. Inhibit the growth of fungi.