本文主要探讨海峡两岸会计师事务所规模与审计质量对经营绩效的影响。透过路径模型分析两岸营收前一百大资料,并将两岸事务所之研究样本分成大型与非大型事务所。实证结果显示,两岸大型事务所规模对审计质量与经营绩效均呈现显著的正向影响,审计质量对其经营绩效亦呈显著的正向影响,然而事务所规模透过审计质量对经营绩效的间接效果只有在大陆大型事务所有显著正向影响。其次,就两岸非大型事务所而言,事务所规模对审计质量呈显著的正向影响,事务所规模对经营绩效之直接影响,只有在台湾地区非大型事务所才显著为正。审计质量对经营绩效,只有在大陆非大型事务所才具有显著正向影响。至于事务所规模透过审计质量而对经营绩效的间接影响,也只有在大陆非大型事务所才具有显著正向影响。此结果意味着,大陆会计师事务所经营绩效主要决定因素是审计质量,然而台湾地区则是事务所规模。在后ECFA时代,本文研究结果提供两岸会计师事务所经营决策之重要参考信息。 This paper mainly discusses the impact of the scale and audit quality of the two sides of the Strait on the operating performance. Through the path model, we analyze the top 100 data before cross-strait revenue and divide the research sample of cross-strait firms into large and non-large firms. The empirical results show that the size of large firms in both sides of the Taiwan Strait has a significant positive impact on audit quality and business performance, and audit quality also has a significant positive impact on its business performance. However, the size of the firm overshadows the business performance through the audit quality The effect has a significant positive impact on major mainland firms. Second, in the case of non-large-scale firms across the Taiwan Strait, the size of the firm has a significant positive impact on the audit quality. The direct impact of the size of the firm on business performance is significant only for non-large firms in Taiwan. The audit quality has a significant positive impact on business performance only in non-major firms in the Mainland. As for the size of the firm, the indirect impact on business performance through audit quality can only have a significant positive impact on non-major firms in the Mainland. This result means that the major determinant of the operating performance of mainland accounting firms is the quality of auditing, whereas Taiwan is the firm’s size. In the post-ECFA era, the findings of this paper provide important reference information for the management decision-making by both banks of accounting firms.