Writing is a subjective and performative activity. Writing ability has multi-facets and compoundness. To understand the examinees`s writing ability accurately and provide effective writing scores, raters first ought to have the competency regarding assessment. Therefore, this study is significant as a fundamental research about rater`s characteristics on the TOPIK writing assessment. 150 scripts of the 47th TOPIK examinees were selected randomly, and were further rated independently by 20 raters. The many-facet Rasch model was used to generate individualized feedback reports on each rater`s relative severity and consistency with respect to particular categories of the rating scale. This study was analyzed using the FACETS ver 3.71.4 program. Overfit and misfit raters showed many difficulties for noticing the difference between assessment factors and interpreting the criteria. Writing raters appear to have much confusion when interpreting the assessment criteria, and especially, overfit and misfit teachers interpret the criteria arbitrarily. The main reason of overfit and misfit is the confusion about assessment factors and criteria in finding basis for scoring. Therefore, there needs to be more training and research is needed for raters based on this type of writing assessment characteristics. This study is recognized significantly in that it collectively examined writing assessment characteristics of writing raters, and visually confirmed the assessment error aspects of writing assessment. (NIIED, Korea University)