Phosphorus (P) is one of the least available major nutrients to the plants in many cropping environments. P deficiency is more critical in highly weathered soils of tropics and subtropics, as well as calcareous/alkaline soils of Mediterranean basin. The production of acid phosphatase and phytase is a potential way for plants to enhance P availability, as a large proportion of soil P (up to 80%) occurs in organic forms. The effect of phosphorus availability on nodule acid phosphatase and phytase activity was studied in 2 lines of common bean (BAT 477 and Coco blanc) under symbiotic nitrogen fixation. Acid phosphatase activities were increased by P deficiency (15 µmol P) in 2 lines, this increase was more pronounced in BAT 477 than in Coco. Under P deficiency, phytase activity was higher in BAT 477 than in Coco, despite this parameter representing only 5 % of that of acid phosphatases, in the 2 lines studied, independent of the P regime. These findings suggest that phytases may be a group of enzymes that constitute acid phosphatases. Regardless of P supply in the culture medium, the content of total P was higher in nodules than in shoots for 2 lines, BAT showed the higher values. P deficiency affected this parameter in nodules, this effect was more pronounced in Coco than in BAT 477 respectively (-30%) and (-20%). Under 15 µmol P, the nodule acid phosphatase activity and the content of total P in nodule were positively correlated. These results suggest that acid phosphatases are involved in hydrolysis of organic phosphorus resulting in elevation of the (Pi) phosphorus pool.