This research was carried out to determine the relationship between worker's health status and work ability index in small scale factories. The data were gathered from 330 workers of Gumi industrial complex, from February to March, 1996. In this study, as questionnaire for the assessment of work ability, We used the work ability index which was developed by Institute of Occupational Health in Finland. The results of the study were summarized as follows; 1) Work ability index was poor in shift work group, more than 9 hours work group, irregular diet group, and stress sensitive group (p<0.01). There were no evident trends of work ability index in sex, marital status, educational level, obesity index, exercise, alcohol drinking and smoking. 2) As comparing work ability index with worker's health status, work ability index was poor in visual correction needed group, urine sugar positive group, and abnormal ALT & AST group (p<0.01) There were no evident trends of work ability index in hearing capacity, blood pressure, hematocrit and urine protein. 3) In the ANOVA was performed to examine the relationship between work ability index and significant factors above 1) and 2). shift work, work hours, diet, stress sensitive and health status were still statistically significant (p<0.05) on work ability index.