According to importance of purchasing decision style, current research have tried to be identified and prioritized styles of purchase decision making on the basis of Sproles and Kendall’ s model. So this is an applied research which was developed to investigate to demonstrate consumer purchase style among different ages of consumer in Tehran. The statistical population of this study is composed of consumers of different age groups who buy from well-known food stores in Tehran. Based on the Cochran formula 2100 individuals have been considered as the statistical sample. For data collection the standard questionnaires were applied. The validity and reliability of the questionnaires were tested and the required changed were applied. As the result show via ANOVA indicated that there are significant differences between six buying styles of eight styles and there is not a significant difference between two styles. The results of data analysis by using Topsis technic for prioritizing styles of purchase decision making of Iranian consumers of different age groups indicated that buying styles of being perfectionistic and high quality conscious were the top priority of teenagers, youth, middle-aged and adults, and styles of being aware of prices and value of exchanged good were the top priority of elders. .