Abstract: OBJECTIVE To discuss the effect of Andrographis paniculata extract (APE) on the expression of cytokines in oral ulcer guinea pigs. METHODS Oral ulcer model of guinea pig was induced by burning the left cheek with 90% phenol solution. Effects of APE on ulcer area, ulcer degree and ulcer tissue pathological changes of oral ulcer guinea pigs were observed. Expressions of tumor necrosis factor-α(TNF-α), interleukin 6 (IL-6) and vascular endothelial growth factor (VEGF) in serum were determined after administered continuously for 5 d. RESULTS Oral ulcer model of guinea pigs was induced by phenol solution successfully. Compared with the model group, the high dosage of APE external group and the Guilin Watermelon Frost group could significantly decrease ulcer area(P<0.01), significantly improve the degree of oral ulcer and the pathological changes of ulcer, significantly reduce levels of TNF-α and IL-6(P<0.01) and significantly express difference of VEGF (P<0.01), there was no significant difference between the two groups. CONCLUSION APE has therapeutic effect on oral ulcer guinea pigs.