This study aims to identify the influence of differentiation strategy, brand image, price perception and promotion to purchase decision on Samyang noodle product in Yogyakarta city. Data were taken from the sample of 100 respondents selected by using purposive sampling data collection technique. The tool used is multiple linear regression method and use validity test, reliability test, classical assumption test, t test, F test, and determinant coefficient (R²). Based on the analysis, it is found that: hypothesis testing by using F test can be known variable of differentiation strategy, brand image, price perception and promotion influence simultaneously to purchasing decision. T test with t test indicating that variable (X1) differentiation strategy and variable (X2) brand image proved to positively and significantly influence to (Y) purchasing decision. While variable (X3) perception of price and variable (X4) showed that both variables have positive and insignificant effect to (Y) purchasing decision. The result of adjusted R square is 41,6% purchasing decision variable can be explained by four independent variable.