The primary purpose of this final project is to identify the influence of product and promotion on purchasing decisions and to find out the most influential variable in purchase decision of Suzuki Motor in PT Indo Sunmotor Gemilang branch Bubakan-Semarang in partial and simultaneous. The sampling technique used was simple random sampling. The research instruments used to collect the data were questionnaires, interview, observation, and literature review. The statistical analysis used is multiple linear regression method, test reliability, test validity, F test, ttest. Multiple linear regression method produced equations Y= 1,864 + 0,514 X1 + 0,363 X2. The test reliability and test validity showed that the data were valid and reliable. The hypothesis was proven using the f test and t-test leading to the conclusion that: product and promotion variables have significant influence on purchasing decisions of Suzuki motor in PT Indo Sunmotor Gemilang branch Bubakan-Semarang. Product is as the dominant variable which needs to be considered and improved. The result of the t-test analysis shows that the product variable resulted t = 6,112 and the promotion variable yields t= 4,357 were bigger than t table 1,664 using 5% scale. It means that product and promotion have a significant impact on purchase decision of Suzuki motor in PT Indo Sunmotor Gemilang branch Bubakan-Semarang. Then the result coefficient of determination (R Squared) was 57,5%, meaning that purchase decision is influenced by the product and promotion. Whereas the other 42,5% is influenced by other variables which are not observed.