PURPOSE: To evaluate the effect of low-intensity pulsed ultrasound（LIPUS） combined with triamcinolone acetonide on oral mucosal ulcer in syrian hamster in several ways, including healing time, contents of superoxide dismutase（SOD）and malondialdehyde (MDA). METHODS: Sixty syrian hamsters were randomly divided into 5 groups, including a baseline group (containing a normal baseline group and a model baseline group, n=6) and 4 experimental groups (LIPUS processing and drug use group, LIPUS group, drug group and a normal control group without any processing, n=12). Four experimental groups and model baseline group were given oxygen free radicals to model the oral mucosal ulcer. At 24 h after the last treatment, the healing time of ulcer, content of SOD and MDA were compared between each group. SPSS 20.0 software package was used for statistical analysis. RESULTS: Compared with LIPUS group,drug group and control group, the healing time of oral mucosal ulcer in LIPUS and drug combined group was shortened. At 24 h after the last treatment, the activity of SOD showed that the LIPUS and drug combined group[(2.32±0.30) U/mgprot] were significantly higher than the model baseline group[(1.48±0.29) U/mgprot], the LIPUS group[(1.83±0.15) U/mgprot], the drug group[(1.76±0.25) U/mgprot] and control group[(1.71±0.18) U/mgprot] (P<0.05). The results of MDA content showed that the LIPUS and drug combined group [(8.17±0.21) nmol/mgprot] were significantly lower than the model baseline group[(9.41±0.22) nmol/mgprot], the LIPUS group[(9.00±0.44) nmol/mgprot], the drug group [(9.04±0.43) nmol/mgprot] and control group[(9.03±0.46) nmol/mgprot] (P<0.05). After oral mucosal ulcer healing, the activity of SOD and MDA showed that the LIPUS and drug combined group, the LIPUS group, the drug group and control group were not significantly different from the normal baseline group (P>0.05). CONCLUSIONS: Low-intensity pulsed ultrasound combined with triamcinolone acetonide can effectively improve the activity of SOD and reduce the contents of MDA in ulcerated tissues, and therefore accelerate the process of ulcer healing．.