The purpose of this study was to investigate effect of robot-assisted hand rehabilitation(Amadeo(R)) on hand motor function in chronic stroke patients. This study used a single-subject experimental design with multiple baselines across individuals. Three chronic stroke survivors with mild to sever motor impairment took part in study. Each participants had 2 weeks interval of starting intervention. Participants received robot-assisted therapy(45min/session. 3session/wk for 6wks). Finger active range of motion(AROM) was assessed by Range of Assessment program in Amadeo(R), and test-retest reliability was verified using Pearson correlation analysis. To investigate effect of Amadeo(R), finger AROM was measured immediately after each sessions and Fugl-Meyer Assessment of Upper extremity, Motor Activity Log, Nine hole peg board test and Jebsen-Taylor hand motor function test were assessed at pre-post intervention. Results were analyzed by visual analysis and comparison of pre-post tests. The test-retest reliability of Range of Assessment was good(r=.99). After robot-assisted therapy, finger AROM of participant 1, 2, and 3 was respectively improved by 18%, 3.6%, and 6% each. Hand motor function of participant 1, 3 was improved on all four tests, but not effect in participant 2. Robot-assisted hand rehabilitation could improve finger AROM and effect on hand motor function in chronic stroke patients.