中文摘要：

因被同一实际控制人所控制，企业集团中的上市公司审计问题呈现出与单个公司不同的特征。以往研究通常关注单个公司，对于集团内多家上市公司的统一审计研究，也仅侧重于经济后果的影响方面。那么，形成企业集团统一审计的影响因素究竟是什么？运用Logit模型对2003至2010年我国A股上市公司中隶属于企业集团的1064个样本进行回归，研究发现，上市公司股东间的代理冲突越严重，越有可能选择集团统一审计；集团内存在地缘关联的公司，更可能选择集团统一审计。进一步研究虽然没有发现上市公司选择集团统一审计是出于业务协同，从而在经济上节省成本、提高效率的显著证据；但是却发现2007年（合）以后，由于制度变迁，业务协同对选择集团统一审计的影响作用显著增强，上市公司在集团内的地缘关联对选择集团统一审计的影响作用显著减弱。

英文摘要：

Controlled by the same ultimate shareholder, listed companies in a group face a different auditor choice from a single public company. The conventional wisdom in the literatures focuses on the single public company, or only pays attention to the economic consequences of hiring the same auditor by different companies in a business group. What are the determinants of unified audit in a business group？ This paper selects a sample of 1064 listed companies from 2003 to 2010 in China＇s A share market, uses the Logit model of regression, and find that companies with more agency conflicts or involved in geographic associations in group are more likely to choose unified audit. Further study does not find evidence that business synergy plays a significant role in the choice of unified audit in terms of economic efficiency. However, due to the institutional improvements, the influence of business synergy on the unified audit choice has been stronger, while the influence of geographic association has been weaker since 2007.