The purpose of this research are to know about influence of psychographic segmentation factors of the buying decision in Alfamart and to know which the most dominant to affect the buying decision in Alfamart. This research is implemented in Banyumanik area with 100 respondents and use purposive sampling technique. The model of the research used questionnaires. This research was uses quantitative descriptive analysis method that is multiple regression linear, normality test, and signification test which used to prove the hypothesis by using SPSS 20.0. the result of this research is showing that partially social class variable was not influential on buying decision in Alfamart. While lifestyle variable and personality variable have a positive influence on buying decision in Alfamart. Personality variable have biggest influence to buying decision in Alfamart. Simultaneously social class variable, lifestyle variable, and personality variable have influence on buying decision in Alfamart by 65.7%.