The objective of this research is to explore how external auditors rely on the work of internal auditors in audit firms in China. This study uses a qualitative method of semi-structured data collection interviews. Semi-structured interviews were conducted with internal auditors and external auditors working in China. On the basis of a summary of the existing literature on internal audit, external audit, the reliance of external audits on internal audit and audit quality, this paper analyses and compares the external auditor’s reliance on internal audit and conceptualizes the results of the data analysis. Nevertheless, according to interviews, at present, small and medium- sized enterprises rarely set up an internal audit department, only large companies and government departments in China set up an internal audit, because, firstly, the cost of an internal audit, secondly , the lack of professional internal audit staff and internal audit outsourcing in China is of this kind of legal form. The study showed that the qualitative analysis has provided evidence of the dependence of external audits on internal audits continue to exist in China. In addition, the study showed that Internal auditing needs to maintain independence and objectivity, while external auditing needs to ensure professionalism, independence and authenticity. To a certain extent, external audit relies on internal audit to save time and improve efficiency in order to improve audit quality in china. However, this dependence is based on the independence of the internal audit and the external audit and cannot be entirely dependent on the authenticity that will lead to the recurrence of similar Yin Guangxia incidents.