Objective; Infectious disease(upper respiratory infection, diarrheal disease) in military force can worsen largely the combat strength. The purpose of this study is to investigate the relation of personal hygiene or life style and infectious disease. Method; The study was conducted over a period of 3 months. This study included 157 healthy male and female sailors and aged ranges between 19 to 49 years. The data was collected by questionnaire. Data included frequency of shower and handwashing, nail clipping, toothbrushing. Answers for this variables were regrouped into two category by frequency. And analyzed by χ2-test with other variables like presence of febrile sense in last three months and common cold, diarrhea in last month. And then, stepwise logistic regression analysis was conducted with variables that were significant in χ2-test. Result; Presence of common cold in last month was related with frequency of shower in a day, severity of stress, frequency of nail clipping. Presence of febrile sense in last three months was related with hours of sleeping in a day, hours of exercise in a week, severity of stress. Diarrheal group did less handwahsing before meal significantly compared with non-diarrheal group. Conclusion; Management of stress, frequent nail clipping and shower, proper sleeping and exercise were needed for preservation of combat strength in military force. And adequate handwashing before meal should be emphasized for prevention of diarrhea.