This study aimed to identify the impact of marketing mix elements on the decision of buying new and used Japanese cars spare parts in the area of east Amman. To achieve the objectives of the study and prove the hypothesis, the researchers' targeted persons using Japanese cars of those who are in the eastern region of Amman, it was done randomly. The study sample was 123 questionnaires by 92.5%. The results showed that the study sample was unanimous on the quality of original spare parts for Japanese cars and they agreed on the competence and characterized by high goodwill. As for the price of Japanese spare parts, results showed that played a major role in determining the quality and that the respondents prefer to buy original spare parts for the traditional with the high price tag and the presence of a traditional alternative and not be waived for product quality in exchange for the lowest price. In addition the study sample found that the parts of the low price and lower quality inappropriate   them with it commensurate with their income. The study showed easy accessed to the industrial cities to buy new and used Japanese spare parts, the time of the sample was appropriate with the stores of the sample time. In contrast, the results proved that it is possible to change and replace the shoddy piece easily after buy it. The study mentions that the quality of the goals, price and location of the stories and advertising campaigns related to the decision of customer buying.  The study recommended that shops should commensurate with the desires of consumers and their purchasing power in the available time and place.