The aims of this paper is to analyze the features of Korean language teacher’s writing assessment based on Many-Facets Rasch model. For that, the 68 Korean language teachers assessed 35 expository writing of middle school students. Then, 6 expository writing was selected randomly and analyzed using free FACETS program. The results are following. First, the range of korean language teachers’ severity was from -1.96 logit(SE=.26) to 2.48 logit(SE=.33). It was showed that severity and consistence of Korean language teachers engaged writing assessment were different. Second, there were differences of Korean language teachers’ severity and consistence according to their gender and career. The female teachers(0.11 logit, SE=0.07) were more severer than male teachers(-0.11 logit, SE=0.03). The range of severity as teachers’ career was from -0.52 logit(SE=0.26) to 0.16 logit(SE=1.1). The severity of teacher experienced 1～5 years was more higher than another teacher. Third, as analyzed subordinate constructs of expository writing assessment, korean language teachers assessed word choice, convention, content, craft, organization highly in order of difficulty. This result will be a helper to develop programs for expertises in students’ writing assessment of Korean language teachers.