Purpose: The present study was conducted with the aim of presenting a professional development model for high school teachers. Methodology: The research is applied in terms of purpose and exploratory in terms of mixed method. In the qualitative section, the statistical population included all experts in education and training sciences in Tehran that a sample of 15 people was selected by purposive sampling using the principle of theoretical saturation from the above community. In the quantitative part, the statistical population included all high school teachers in Tehran that 382 people were selected by stepwise cluster sampling. In order to collect data in the qualitative part, an in-depth semi-structured interview with 5 open-ended questions was used, and in the quantitative part, a researcher-made questionnaire was used to design a career development model. Qualitative data analysis was performed using thematic analysis method and partial least squares method was used to analyze quantitative data. Findings showed that the components of professional development according to experts included three dimensions of professional knowledge, professional commitment and professional ability. Findings: The results of factor analysis on 25 items of professional development model showed that the factor loads of the items of each factor and the relevant t-index had a factor load of more than 0.4. Also, all variables had the mean and extracted variance above 0.5. Also, in order to determine the reliability of data collection tools, Cronbach's alpha method was used. The values of these coefficients for all variables were above 0.7, which indicated the appropriate reliability of the questionnaire. There is a strong link between the role of human capital and the development of countries. Conclusion: Human capital growth is a set of knowledge, skills and characteristics that lead a person to individual, organizational and social success.
