Objective To evaluate the clinical effect of posterior teeth food impaction because of class Ⅱ cavity treated with resin inlay .Methods A total of 140 teeth with posterior teeth food impaction caused by bad proximal contact were averagely randomly divided into two groups ,70 teeth treated with resin inlay and 70 teeth treated with resin filling .The clinical effect was analyzed with modified USPHS 1 year later .Results The success rate in resin inlay group (95 .46% ) was superior to resin filling group (79 . 37% ) ,with significant difference(P<0 .05) .The resin inlay group had 3 defect cases with 1 edge coloring and 2 edge incomplete . While the resin filling group had 11 defect cases with 2 edge coloring ,3 edge incomplete ,2 abrasion ,4 bad proxima contraction and 2 cases filled with fracturing .Conclusion Resin inlay can better restore food impaction with class Ⅱ cavity compared with resin filling .