In many literatures, the personality traits of employees can effectively predict job performance. This study aims to verify the employment services specialists’ personality traits how to affect the job performance. It examined the moderating effect of key performance indicator on the relationship between personality traits and job performance. This study has adopted SPSS for statistical analysis. The study methods consist of : factor analysis, reliability analysis, descriptive statistics, subsequent inspection, Pearson correlated analysis, regression analysis and so on. The results are as follows: 1. The researchers found that personality traits have a significant impact on contextual performance. 2. The results of this study showed that Conscientiousness is most correlated to task performance. 3. Key performance indicators have no moderating effect between personality traits and job performance.