Abstract: Over the past century, researchers and practitioners adopted a variety of personality tests in personnel selection, expecting that personality tests could accurately select employees with high-quality and high-performance. In order to verify the validity of personality tests used in personnel selection, the research hotspots focused on the relationship between personality traits and job performance. Due to the lack of a unified universal model of personality traits, personality traits did not predict job performance significantly in previous studies. With general acceptance of Big Five Personality theory, Big Five Personality was widely used in personnel evaluation and personnel selection, which consequently promoted researches to explore the relationship between personality traits and job performance. Numerous studies demonstrated that personality traits under the theoretical framework of Big Five Personality could predict job performance, meanwhile researchers proposed that perhaps there might be some kind of moderator in the impacts of personality traits on job performance. By questionnaire, this research studied correlations between Big Five Personality and job performance under the influences of work attitude. In previous studies, self-report questionnaire was applied in the assessment of job performance more frequently. With a variety of objective job performance data of frontline production staff working as the criterion, this research probed into the impacts of personality traits on job performance, assuming that work attitude was the moderator. The results of surveying 1,277 frontline staff members in public transportation illustrate that personality traits are significantly related to job performance, with work attitude acting as a moderator in this relationship. Among frontline staff members in public transportation, conscientiousness is a good predictor of task performance, while extraversion predicts contextual performance well. As a consequence, priority should be given to the candidates with high conscientiousness and low extraversion. Candidates with high neurotic tendencies should be avoided. With high work attitude, personality traits have closer contacts with task performance, Conscientiousness and extraversion are good predictors of job performance; While with low work attitude, personality traits are more closely related to contextual performance, agreeableness and openness predict job performance well. The completion of work is emphasized in the high-attitude environment, while coordination of relations is more valued in the low-attitude environment. Work attitude as a moderator affects the requirements of job performance of personality traits.

Key words: Big Five personality, job performance, work attitude, task performance, contextual performance