The purpose of this study is the effect of tax incentives on tax collection in the comprehensive tax plan using Grounded theory and the structural equation model. The method used in this study was a hybrid method including a qualitative method based on the Grounded theory approach and a quantitative method based on the structural equation approach. The research was conducted in three stages. In the first step, which was done qualitatively, the data are collected through structured interviews with a statistical sample (experts). In the second stage, key themes were extracted and converted into the corresponding model. In the last step, the extracted model was tested, which was done quantitatively. At the qualitative stage, the statistical population consists of two groups. The first group includes specialists and experts who have been faculty members of universities and the second group includes experts and managers who have at least 10 years of experience in the field of finance and taxation. A sampling at this stage of the research was purposeful and 12 in-depth and semi-structured interviews were conducted using theoretical sampling and the snowball technique of managers, tax experts and financial management. In a small part of the statistical population of the study, the taxpayers were the General Department of Tax Affairs of Mazandaran Province. According to the survey, the statistical population was 40,000 companies and based on the Morgan table, the sample size was 380 files. In the present study, the data obtained from the text of the interviews were analyzed by MAXQDA software in order to increase the accuracy and speed of the research. In this research, 98 codes extracted from 12 detailed interviews with experts and specialists in the field of research have become 33 more abstract concepts and finally, 5 categories have been identified. The coefficient of achievement of structural equations shows that the variables of Ease of understanding and usefulness of the rules, Security and speed rules, Rules Support Services, Effectiveness of laws, and Conditions for facilitating the rules have a positive and significant effect on tax payments by taxpayers.