Objective To observe the effect of Reyusan and Etiasa in treating Ulcerative Colitis of damp heat in the large intestine stagnation type， and to investigate Reyusan on the mechanism whether Ulcerative Colitis treated by lowering TNF-αand CRP. Methods The patients of active Ulcerative Colitis were randomly divided into treatment group and control group（Mesalazine only）， compared two groups of symptom effects and main symptoms scores， and grouped by severity of serum before and after treatment of TNF-α， CRP concentrations. Results The total effective rate of treatment group was up to 92%， the control group was 72%（P<0.05）； there was no significant difference between the two groups without medicines（P>0.05）； after taking pills， the serum levels of TNF-α and CRP in patients with mild to moderate， were significantly lower in treatment group than those in the control group（P<0.05， P＜0.01）， but no significant differences in patients with severe（P>0.05）； there was a significant difference before and after treatment of CRP（P<0.05）. Conclusion The treatment group had better effect than control group in syndrome， Reyusan plays an important role in lowering the serum levels of TNF-αand CRP， the reduction in TNF-αand CRP are greater than Etiasa.