The purpose of this study was to identify and measure the factors affecting talent management in the national gas industry. So, the qualitative and quantitative approaches have been used. Delphi approach in the qualitative part and the Shannon entropy in the quantitative part have been used. For this purpose, a team of 15 experts, including organizational managers as well as academic professors, was selected and the Delphi approach steps have done according to their views. The result of this section, it has been identified 42 variables within the 10 key variables of personal development, organizational strategy, recruitment and selection, performance management, training, compensation, discipline, political factors, labor supply, and laws and regulations that have influenced talent management. Based on the results of the Delphi approach, the effect of the 10 factors on talent management was equal, while some factors may be more effective than others. So, the weighting of the main variables based on the Shannon entropy method according to the opinions of 10 experts was considered. The results showed that performance management has the highest importance and personal development has the lowest importance in talent management.