The purpose of this study was to verify the effects of Sea tangle pellet(fiber supplements) on the constipation of institutionalized aged. Method: This study was conducted from September to December 2007 and a nonequivalent pretest-posttest quasi-experimental design was used. Data were collected using interviews, questionnaires and observational measurement including frequency of bowel movements, stool color, straining, abdominal discomfort/pain and change of symptoms before and during supplementation. Forty-six subjects were divided into two groups, a control group and an experimental group: The experimental group received 4g/day of Sea tangle pellet for 4 weeks. Data were analyzed by repeated measures of ANOVA using the SPSS program. Results: Aged in the experimental group had a significant improvement in frequency of defecation, straining, abdominal discomfort/pain and changes in symptoms compared to those in the control group. Conclusion: In institutionalized aged with constipation, fiber suppplements using Sea tangle pellets significantly improved constipation related symptoms without serious side effect.