This research is an exploratory study with purposes to understand the contents and implementation of the implicit standards of department managers’performance evaluation. The research found that all interviewed managers have personal implicit standards on performance evaluation. Some of them can clearly express their implicit standards of performance evaluation but some couldn't specific describe. The contents of implicit standards depend on departments’current situation, future development, the degree of goal achievement and employees ability.while effectiveness of implicit performance evaluation depends on company evaluation system and other external factors. Moreover, the promotion decision not only depends on the public performance evaluation results but also on implicit standards of evaluation. To decrease the impact of implicit evaluation, the managers will reduce the influence of personal standards and invite other managers participating the performance evaluation process to achieve justice and avoid conflicts and arguments.