This study aims to identify and explain the effect of brand extension to the brand image , brand image to purchase intention and brand extension to purchase intention . This type of research used in this research is the explanation (explanatory research). This study uses a quantitative approach that is formed from a number of theoretical concepts hypotheses and assumptions before collecting field data. Brand extension is examined in this study is the brand Lifebuoy. The population in this study were students S1 and D3 Brawaijaya University of Malang that use the parent product brand Lifebuoy. The samples used in this study was 117 respondents. The sampling technique used in this study is a non-probability sampling. How sampling with purposive sampling. The instrument of this research by using questionnaires. The analysis used is descriptive analysis and path analysis (path analysis). The results of this study indicate the brand extension is shown to have a significant influence on brand image. Brand image is shown to have a significant influence on purchase intention. Brand extension is shown to have a significant influence on purchase intention. Brand image is proven as an intervening variable in the relationship between the expansion of the brand with the buying interest.