this goal, first the factors and indicators affecting the independent audit assurance services were defined based on the field analysis technique and then these factors and indicators were classified. According to this goal, this project is an innovative combination of consecutive and instrumental model type, design, and development model based on the design criteria of this model. Members of the Iranian Society of Certified Public Accountants have led to the definition of research model criteria by using the case study research method and semi-structured interviews of managers and partners of auditing firms and auditing firms. Based on interviews and analysis of previous studies, factors affecting the pricing model of independent audit assurance services were identified. 50 codes were examined which were classified into 9 groups based on axial coding. These factors include corporate governance, corporate ownership structure, internal factors of the company, external factors of the company, factors of the auditing firm, characteristics of managers and owners, financial and accounting factors, audit characteristics, and competitive market auditing. To determine the degree of importance of the identified criteria, the demitel phase group decision-making technique was used. Based on the obtained results, financial and accounting factors are at the highest level of impact (9.91). Financial and accounting factors refer to the criteria of free float, the percentage of ownership of major shareholders, audit risk, the ratio of total liabilities to total assets.