The job stress is rising as a social issue in all industries. So many manufacturing companies have been trying to prevent the job stress. Recently, the job stress is the important cause which lead to WMSDs, depressive disorder, anxiety disorder and sleep disturbance. However, the cause of the job stress is very variety. So management is very difficult. The purpose of this study is to investigate the group of the job stress by Karasek model from workers in auto part manufacturing company. The survey was using Karasek job stress model and was administered to 181 workers of auto part manufacturing company. Job demand median and job decision median was in 30.0 and 50.0. From this study, following results were obtained. 1) The gender of workers according to the groups of job stress was statistically significant(p<0.05). 2) The duration of working of workers according to the groups of job stress was statistically significant(p<0.05). 3) The intensity of work of workers according to the groups of job stress was statistically significant(p<0.01). The result of this study will help to identify the group of job stress and improve personal coping ability, systematic measure of company.