The purpose of this study is to see how the implementation of e-procurement system via the Electronic Procurement Service (LPSE) Government of Riau Islands province, which had been adopted in 2008. The study also want to see how they affect the political process towards the implementation of e-procurement. The method in this study is a mix method. Data collection techniques used in this research are questionnaires, interviews and documentation. While the goal of this research is the party who understand in detail how the process of implementing e-procurement system in the province of Riau Islands. Results from this study is that the implementation of e-procurement system in Riau Islands province has been run very effectively with the effectiveness index value of 3.27. Parameters that contribute to the effectiveness of the implementation is the purpose and the type of website system (3.33), regulation (3.31) clarity of e-procurement planning (3.28), human resources support (3.27), efficiency and effectiveness ( 3.25), support infrastructure is the lowest parameter with a value of 3.11. At the level of the political process, imlementasi eprocurement system is significantly affected by opportunistic behavior of agent (22.42%), clarity of information principal (16.87%), clarity of information agent (15.37%), principal opportunistic behavior (13, 40%), principal contracting mechanisms (13.04%), the mechanism of contract agent (16.30%). Total influence the political process towards the implementation of e-procurement system in LPSE Riau Islands Province amounted to 97.40% state that has a very strong influence on the implementation of e-procurement system in LPSE Riau Islands Province. while 2,60% influenced by other variables.