Backgrounds: According to a high interest in health these days, a bicycle is being highlighted as a means of leisure activity and auxiliary transportation means. Along with an increase in this interest, there is tendency that even the width of bicycle utilization gets diverse and that bicycle accident is also rapidly growing. Purpose: The purpose of this study was to suggest a prevention measure available for reducing occurrence of bicycle accidents by analyzing the Epidemiological characteristics according to age and injury severity in bicycle-injured patients. Methods: This study analyzed 115 materials suitable for this study by examining a medical record of patients, who received the hospitalized treatment owing to bicycle accident from January 1, 2011 to December 31 at one general hospital in S city. Results: The male-and-female ratio of bicycle-injured patients stood at about 7:3. The average age was 38.14(${pm}21.59$) years old. The largest injury happened in 40-59 years old(31.3%). The averagely hospitalized period was 17.33(${pm}18.12$) days. Injury severity was the ratio of 2:8 in a mild case versus a serious case. As for drinking and smoking characteristics according to age, the injury occurred the most in between 40 and 59 years old for people with drinking and smoking and in under 19 years for people without drinking and smoking. According to injury severity, the ratio of serious case got higher in the higher age. This was indicated(${chi}^2$=15.675, p=0.001) to be statistically significant. Conclusion: In this study, a bicycle accident was indicated to have high injury risk in young children, adolescents, and old-age group. Prevention measure and publicity are demanded for reducing injury occurrence such as the prevention education for bicycle accident and wearing protective gear focusing on the ages of corresponding to groups with risk of injury occurrence. In addition, the security of safe movement route is necessarily demanded in order to increase application level as an auxiliary transportation means.