60 patients with pathologically diagnosed erosive lichen planus of bilateral buccal mucosa were included.The lesion on one side was treated by local application of triamcinolone acetonide dental paste(test group),the lesion on the other side without treatment was used in the control group.7,1 4,21 and 28 d after treatment the pain level and the lesion situation scores in the test group decreased significantly (P <0.001 ),and lower than those in the control group at the same time point(P <0.05).No adverse reaction was found in the 2 groups. Triamcinolone Acetonide Dental Paste is effective in the treatment of erosive oral lichen planus.