The emergence and development of internal audit is a long historical process, which has gone through three stages: ancient internal audit, modern internal audit and modern internal audit. Modern internal audit began in America. 194 1 year is considered as the beginning of modern internal audit. Before 1940, in the United States, internal audit was only the assistant of external accounting companies. At 194 1, Victor. Brink completed his doctoral thesis in new york University, and expounded the breakthrough research results of internal audit, including the nature and scope of internal audit. Brink pointed out that internal audit should be the server of company management, not the assistant of external audit (external accounting company audit). With this paper, Brink became the "originator" of the "internal audit" discipline in the United States. In the same year, JohnBThurston, director of the internal audit department of North American companies, wrote a monograph on internal audit, entitled "Principles and Techniques of Internal Audit". Brink also published the first comprehensive and systematic book "Principles and Practice of Internal Auditing" in the United States on 1942. This book has been constantly updated, and the fifth edition was published on 200 1. The above events show that the system theory of internal audit has begun to take shape, which is the first turning point of internal audit.

From 65438 to 0978, the International Institute of Internal Auditors (IIA) formally promulgated the Code of Practice for Internal Auditing. This is the embryonic form of "internal auditing standards". Therefore, 1978 is a critical period for the development of internal audit in the United States, and it is also the second turning point in the historical development of internal audit. The first page of the Code of Practice for Internal Auditing is a comprehensive and rigorous definition of the concept of "internal auditing", which was quite perfect in the economic and auditing fields at that time. After the promulgation of this standard, it has been widely recognized by the auditing circles all over the world and has been translated into 9 languages.

From June, 65438 to June, 1999, the International Association of Internal Auditors and its research fund, after repeated discussions, research and soliciting opinions from all sides, formally promulgated the Internal Auditing Practice Framework. Just like the framework of financial accounting standards, the practical framework of internal auditing is the core of internal auditing standards, so1June 1999 is the third "historic turning point" in the historical development of internal auditing in the United States. Relevant documents have been issued one after another.