This article attempts to examine the impact of the partnership agreement with the EU in 2005 on the European direct investment flows to Algeria, which have been considered to be an important factor in the success of the partnership path in its economic aspect and the achievement of its objectives. By examining what was actually achieved from these flows during the period 2005-2016, it appears that it was below the expected level by the Algerian partner, with a total value of only $ 8.66 billion, at an annual rate of $ 867 million. Parallel to this, the quality of the economic climate has been eroded by the triad of rents economy, corruption and the expansion of the parallel economy, which affected the business environment that suffers already from many obstacles, despite the efforts made in order to improve the investment environment through the development of many legislative and regulatory frameworks that have came with many facilities and incentives since 1993 .