近年来中国颁布了一系列文件加强对内部控制的建设，内控和事务所审计作为保障盈余质量的两种重要方法，从公司内外两部分发生作用，它们是否能真正有效地抑制盈余管理行为，以及它们发挥的作用具有替代性还是互补性，本文以2010年——2014年沪深两市A股上市公司样本探讨上述问题，在研究当中将盈余管理分为应计盈余管理和真实盈余管理两个部分分别讨论，以修正琼斯模型衡量应计盈余管理，以Roychowdhury提出的模型衡量真实盈余管理，探究内部控制、会计师事务所任期和盈余管理之间的关系。运用STATA软件对变量进行多元回归分析，得到以下结论：内部控制质量的提高有助于抑制应计盈余管理，对于真实盈余管理作用有限，而会计师事务所任期增长对于应计和真实盈余管理行为都有抑制作用，同时内部控制和事务所任期在抑制盈余管理的过程中存在替代作用。

In recent years, China has passed a series of documents to strengthen the construction of internal control. The internal control and auditing from accounting firm are important ways to ensure easrnings quality, and this article will discuss whether they can inhibit the earnings managenent. This study use the sample of A-share public companies in Shanghai and Shenzhen Stock Exchange from 2010 to 2014. The earnings management is divided into accural earnings management and real earnings management, the modified Jones model is used to measure the former and the latter is measured by models built by Roychowdhury. Through the multiple regression analysis, this paper draws conclusions as below. Firstly, the improvement of internal control can inhibit the accural earnings management, but it has no effect on real earnings management. Secondly, lengthening the audit firm tenure can limit earnings management, both accural and real ernings management. Finally, the internal control and the audit firm tenure have substitution effect in the process of inhibiting earnings management.