The researcher combines Multi-Stage Dynamic Assessment (MSDA) model with error detection tasks to facilitate the learning potential of MPS checking performance for first graders, and investigates the interrelationships between solving with checking performance. Taking the between paired grouping experimental design to proceed study. The screened samples are 26 by pre-testing, and paired 13 to each group. One group is mediated by multi session dynamic assessment, the other take self-practice. Then two groups accept needed testing. Next the data are analyzed by adequate statistical methods. The simple gain scores of treatment group on checking performance are better than counterpart significantly. The effectiveness of cumulative facilitation, potential discrimination, deficiency diagnosis and prescription for multi session dynamic assessment are found in treatment group. There is medium positive correlation existed between solving and checking performance also.