The objectives of this were to investigate the response of Lupinus albus sp. to phosphate rock (PR) as a source of phosphorus (P) nutrition, and to study the role organic acid (Citric and Malic) in phosphorus dissolution from PR. Tow experiments were conducted: 1) A greenhouse pot experiment, in order to study the response of white lupin to the application of PR and Triple super phosphate TSP at three application rates (100- 450-800 ppm). 2)- A laboratory experiment in order to study the role of Citric and Malic acids concentration and initial pH in P- release from PR. The results showed that Lupinus albus sp. was able to use PR for P-nutrition, and has a relative agronomic effectiveness of 61% when compared to TSP. The possible Exuded organic acids such as Citric and Malic were responsible for PR dissolution due to tow mechanisms: 64% of PR dissolution was due to pH decrease in the rhizosphere area, and 34% due to chelating of calcium cations. PR dissolution was increased by the increase organic acid concentration, but decreased when the initial pH value increased. Dissolution was always more pronounced with citric than malic acid.