Recently, since the interest with well-being has been getting higher than ever, people want reliable source of information related with health and medical treatment. Because of the characteristics of information related with medical care, there have been difficulties to find the information from books, television and internet surfing, for treating disease. Misinformation that can be obtained when considering dangerous situations or side effects, the role of the e-Health system is becoming more important. The objective of this study is an analysis of correlation and effect among patient`s information need, e-Health system use and system outcome. To achieve the object of this study, e-Health system had been given to patients of breast cancer in Wisconsin and Detroit for 16 weeks. As a result, 282 sample was gathered and modified to meet purpose of the study. As a result, the information needs of patients due to the performance of the e-Health systems and shown to affect even the perception of patients` emotional and physical health and social support.