The aim of this study was to develop reading ability test using eye-tracking technology. This study was to analysis and categorize the reading ability assessment constructs and eye movement variables to detect reading disability or reading problem. Reading ability assessment constructs were decoding and reading comprehension. Decoding construcs had three subconstrucs: 1) phonemic awareness, 2) word recogntion, 3) reading fluency. Reading comrehension construcs had three subconstrucs: 1) literal comrehension, 2) Inferencial comprehension, 3) critical comprehension. Reader s eye movement were measured to diagnose and detect reading problems using eye-tracker technology. When decoding ability is measured, reader(subject) see print stimuli, then read aloud and eye-tracker measure eye-voice span, fixation of correct target(ex. letter or word) in presented text. When reading comprehension ability is measured, reader(subject) read questions and reading passage(or text), then they reread to find correct answer. At this time, eye-tracker measured reader(subject) s fixations, saccadesin, regressions in AOI(Area of Interest) which involved important informantion or evidences to judge correct answers.