<p>Drawing on Person–Environment Fit Theory and Social Exchange Theory, this study examined the effects of supervisor–subordinate congruence in emotional appraisal ability on unethical pro-supervisor behavior and its underlying mechanism. Specifically, the results of a scenario simulation experiment and a multiphasic questionnaire design showed that (1) Congruence in supervisor-subordinate emotional appraisal ability promotes supervisor-subordinate guanxi and unethical pro-supervisor behavior more effectively than situations of incongruence. (2) In congruence situations, high supervisor-high subordinate emotional appraisal ability is more likely to promote supervisor-subordinate guanxi and unethical pro-supervisor behavior than low supervisor-low subordinate emotional appraisal ability. (3) In incongruence situations, a scenario experiment (Study 1) showed that low supervisor - high subordinate emotional appraisal ability is more likely to promote supervisor-subordinate guanxi and unethical pro-supervisor behavior than high supervisor - low subordinate emotional appraisal ability; however, this asymmetric effect on supervisor-subordinate guanxi was not replicated in the questionnaire survey (Study 2). (4) Supervisor-subordinate guanxi mediates between supervisor-subordinate emotional appraisal ability congruence and unethical pro-supervisor behavior. (5) The moderating effect of subordinate’s gender on the congruence of emotional appraisal ability through the mediating effect of supervisor-subordinate guanxi on unethical pro-supervisor behavior is not significant.</p>