The main purpose of this study was to investigate the mathematical learning effectsof dynamic assessment on resource room students at the junior high school level. Theparticipants consisted of 48 resource room students from two junior high schools inTauyuan county. The results indicated that there were significant differences in both thepost-test and post-post-test scores for the treatment group and comparison group.Therefore, the researchers suggest that the learning potential assessment device ishelpful for math resource room teachers who are seeking a more effective way to bothassess and scaffold special education students’ abilities.