Yova Haura Nofit, Effect of Product Quality Againsts Member?s Purchasing Products Decision in Cooperation of Employees Indocement Sharia Unit With Knowledge as Moderator Variables. Thesis, Department of Islamic Banking. Faculty of Islamic Studies, University of Muhammadiyah Prof. DR. HAMKA This study aimed to see how the quality of a product affects the member's decision to purchase the product at the Cooperation Employees Indocement Sharia Unit. Research carried out on members of the Cooperation of Employees Indocement Sharia Unit. The questionnaire was given to 70 members who fills the whole complete existing questionnaire items. Variable measurement technique research using Likert scale. Results of testing with Simple Linear Regression and Moderated Regression Analysis (MRA) indicates that the variable quality of the products has positive effect by 54% and significantly to the members in making a purchase decision in Cooperation of Employees Indocement Sharia Unit. Variable knowledge gives the role of moderation to strengthen the effect of the product on the decision of members in making a purchase at the Cooperation of Employees Indocement Sharia Unit due to the interaction of independent variables with moderator variables significantly influence the purchasing decisions of 0.000, and the coefficient of determination of the interaction of 0.758 is greater than the value of the coefficient of determination variables quality products tested without including the role of the moderator is equal to 0.740.