Objective To explore the possible mechanism of Jianpi Bushen Qingchang Formula（健脾补肾清肠方） in the treatment of ulcerative colitis. Methods A rat model of ulcerative colitis was established with trinitrobenzene sulfonic acid and ethanol enema. The rats that were successfully modeled were randomly divided into a model group

Jianpi Bushen Qingchang Formula low

medium and high dose group

and a normal group

with 10 rats in each group. After the model was established

Jianpi Bushen Qingchang Formula low

medium and high doses group were given Jianpi Bushen Qingchang Formula suspension 3.4

6.8

13.6 g/（kg·d） respectively by gavage

and the normal group and model group were given distilled water 1 ml/（100 g·d） by gavage. After 10 days

the colon tissue was taken for pathological observation. The serum and colon tissue interleukin 1β（IL-1β）

interleukin 6（IL-6）

interleukin 8（IL-8） and tumor necrosis factor α（TNF-α） were detected by ELISA. The expression of IL-6 mRNA in colon tissue was detected by RT-qPCR

and the Janus kinase 2（JAK2）

signal transducer and activator of transcription 3（STAT3） protein and the expression level of phosphorylated protein were detected by Western blot. Results The pathological results showed that the mucosal structure of the colon tissue of the normal group was complete

and the glands were arranged neatly; the colon mucosal structure of the model group was seriously damaged

the glands were arranged disorderly or missing

and a large number of inflammatory cell infiltrations were seen; the colonic glands were less damaged and the structure basically returned to normal in Jianpi Bushen Qingchang Formula high dose group

while the mucosa recovered a little

and some inflammatory cells were infiltrated in Jianpi Bushen Qingchang Formula low-dose and medium-dose group. Compared with the normal group

the contents of IL-6

IL-1β

IL-8 and TNF-α in the colon tissue and serum

the expression of IL-6 mRNA in the colon tissue

p-JAK2/JAK2 and p-STAT3/STAT3 values were significantly increased in the model group（P<0.01）; compared with the model group

the above indicators of the low

medium

and high dose groups of Jianpi Bushen Qingchang Formula were reduced to varying degrees（P<0.05 or P<0.01）

and the improvement of indexes of Jianpi Bushen Qingchang Formula high-dose group was most significant（P<0.05 or P<0.01）. Conclusion Jianpi Bushen Qingchang Formula can alleviate the inflammation in the colon tissue of ulcerative colitis model rats

and repairing the damaged mucosa

and inhibiting the IL-6/JAK2/STAT3 signaling pathway in the colon tissue

and may be one of its mechanisms.