Abstract: The internal control in accounting firms is an institutional protection to improve their quality control ability, risk control ability and market competitiveness. Starting from the system theory and taking the auditing operation process as the core, this paper analyzes the urgency of structuring the internal control in accounting firms and its foundational theories. On the basis of the existing internal-control theories and combining the characteristics of the CPA profession, this paper also analyzes the definition, goals and boundary of internal control in accounting firms and the path and principles for the construction.

Key words: accounting firms; internal control；urgency；auditing process；path and principles