The life expectancy of the Korean people at birth increased by 17.1 years from 65.6 years in 1970 to 82.7 years in 2007. Infant mortality, on the other hand, decreased by more than one-tenth from 45 per 1,000 infants in 1970 to 4.1 in 2006. Although the health standards for Koreans improved remarkably in such a short period of time, health care spending and premature deaths due to chronic diseases, in particular of lifestyle habits, are as much as a burden for Korea as they are for other OECD countries. Chronic illnesses are the main cause of disability and death around the world, including in Korea. According to Sassi and Hurst (2008), 60% of the world's population dies from chronic illnesses. It is a well-known fact that the incidence of chronic diseases is closely related to lifestyle habits such as smoking, drinking and physical activities. The medical cost expenditure spent for obesity-related diseases takes up 5.5%～7.8% of the total medical cost in the U.S. (Kortt et al, 1998). In the case of Canada, 2.5% (as of 1999) of the medical cost is reported to be spent due to lack of exercise (Latzmarzyk et al, 2000). It is reported that once the risk factors such as smoking, drinking and obesity are eliminated thanks to the change in lifestyle habits, great benefits are reaped. For instance, when the Finnish government intervened to change the lifestyle habits of adult males for a period of 25 years, it was reported that the death rate caused by cardiovascular diseases dropped by 68%, coronary-artery disease by 73%, cancer by 44%, lung cancer by 71%, and overall death rate caused by all other factors by 49% (Sassi and Hurst, 2008). The socioeconomic cost in Korea incurred from illnesses in 2007 was estimated to be 56.633 trillion won, or 6.28% of GDP (Young-Ho Jung, 2009). Of this figure, the cost for treating cerebrocardiovascular diseases accounted for about 13.92%, which included 3.882 trillion won for hospitalization and outpatient treatment, 86.4 billion won for transportation, 387.8 billion won for caregivers' cost, 3.2455 trillion won in the loss of income resulting from premature death, and 1.751 trillion won in the loss of productivity caused by hospitalization and outpatient treatment. In this report, a micro-analysis is conducted on lifetime medical cost spent by individuals resulting from obesity and smoking, major causes of cerebrocardiovascular diseases and life expectancy, in order to obtain basic data for developing policies related to future health improvement and health and medicine. Lifetime medical cost per person caused by obesity and smoking was calculated, taking into consideration such changes as individual's sex, age, status of the diseased at the microeconomic level. Moreover, the benefits of health improvement from managing obesity and smoking, which are expected to bring out mid- to long-term financial reduction, were analyzed using the Markov simulation model. The lifetime medical cost of stroke caused by obesity and the cost caused by smoking were compared and analyzed. In section 2, precedent research is studied to analyze lifetime medical cost. In section 3, a brief explanation of the conceptual framework of the model analyzed in this report is followed by the analysis method and sources used to produce the lifetime medical cost of obesity. The lifetime medical cost of stroke, one of the major causes of death and one of the heaviest socioeconomic burdens of Korea, is estimated under the assumption of the current obesity rate. The financial reduction benefit in the mid- to long-term perspective is also reviewed by controlling obesity. To make an analysis on the stroke, the target group included focused on I60-I69, G45 from 2004 to 2008. An overview of the analysis is shown in Diagram 1. In section 4, the analysis outcome produced using the analysis method mentioned in section 3 was described. The last section, section 5, discusses the contemplations and conclusions.