Abstract: Objective To study the effect of volatile oil of rhizoma atractylodis (VRA) on the improvement of ulcerative colitis (UC) in rats. Methods The rat model of UC was established with 5% 2,4,6-trinitrobenzenesulfonic acid enema. The model rats were randomly divided into model group, positive control group (gavage mesalamine 0.36 g/kg), low dose, medial dose and high dose groups (gavage VRA 1, 2 ,4 g/kg respectively), with 10 rats in each group. Another 10 rats were set in the control group (gavage equal volume distilled water). Rats in each group were given the drug (or distilled water) once a day for 10 days. The changes of body weights before modeling, before and after administration were recorded in each group. After the last administration, colon tissues of rats were taken, and pathological changes were observed by HE staining. The levels of interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) in colon tissue were determined by enzyme linked immunosorbent assay (ELISA). Belin1 and P62 mRNA expressions were detected by real-time PCR. LC3 protein expressions were detected by Western blot assay. Results Compared with the control group, the model group showed the decreased body mass, shedding of colonic mucosal epithelial cells, distortion or atrophy of crypt, and infiltration of inflammatory cells. The levels of IL-6 and TNF-α in colon tissues were increased, and the mRNA levels of P62 and Beclin 1 were increased (P＜0.05). There were no significant differences in the levels of LC3Ⅱ/Ⅰprotein expressions between control group and model group (P＞0.05). Compared with the model group, rats in the medial dose group, high dose group and the positive control group increased in body weight after administration. The levels of IL-6 and TNF-α were significantly decreased. Beclin 1 and P62 mRNA expressions were significantly up-regulated. The mRNA levels of Beclin 1 and P62 were significantly increased in the high dose group and positive control group than those of model group (P＜0.05). There were no significant differences in the changes of each index between low dose group and model group (P＞0.05). Conclusion VRA can improve the pathological damage of the colon tissue in UC model rats, reduce the levels of lL-6 and TNF-α in colon tissue, which may be related to the up-regulation of Beclin 1, P62 mRNA and LC3 Ⅱ/Ⅰ relative protein expression.