The purpose of the present study was threefold: (1)to explore the effect of computerized dynamic assessment on fifth graders' reading comprehension, (2)to examine assessment-information gathered from designed dynamic assessments, and (3)to investigate the applicability of the computerization of dynamic assessment on fifth graders' reading comprehension tests. The subjects were seventy fifth graders, with thirty-five assigned to the control group and thirty-five the experimental group who took computerized dynamic assessments. Data collected form pre- and post-tests were analyzed to yield insight into the field of computerized dynamic assessment. The results indicated that (1)the designed computerized dynamic assessment used in the present study increased fifth graders' reading comprehension ability, (2)students with assessment, (3)time spent on the second computerized dynamic assessment was less than that of the first one, (4)the subjects' scores form the second computerized dynamic assessment were higher than those from the first computerized dynamic assessment, (5)computerized dynamic assessment offered additional assessment information such as time for assessment and quantity of assistance.