The purpose of this study to examine the effect of variable brand image that is favorability of brand association, uniqueness of brand association and Strength of brand association in multiple, partially and dominant of purchasing decisions product simPATI at booth Telkomsel MATOS. The number of this study amounted 100 of customer product simPATI. Sampling techniques used reasearch is using accidental sampling. The data analysis used by regresion linier analysis. The data collection was done by distributing questionare that been tasted validity and realibility. Results from this study that brand image variables together significantly influence purchasing decisions, dominant influence on purchasing decisions is variable Strength of brand association, while the variables that effect but no significant effect on purchasing decisions is the favorability of brand association.