The population over 65 years of age in Korea will be 10.3% of the entire population in 2008 indicating that Korea is already in an aging society. In addition, it is expected that Korea will be in an aged society in 2018 (population over 65 years of age : 14.3%) and that it will be in a post-aged society in 2026 (20.8%). Consequently, aged workers may also increase. It is well-known that the possibility to work longer and to live better is highly related to the work ability of individual. The objective of this study was to evaluate the work ability of each age group using the Work Ability Index(WAI) in the shipbuilding industry, and to assess the effects of social psychological stress, drinking characteristics, smoking characteristics, etc. on the WAI score. The results showed no significant difference on the effects of aging, drinking, and smoking characteristics. Interestingly, a statistical analysis on the effects of social psychological stress revealed a significant difference by stress levels. The difference of the average WAI score between the healthy group and the high risk group was about 10 points. Based on this result, it can be concluded that the stress level is an influential factor on WAI.