Abstract: Syrian Arab Republic is one of the producing and exporting countries of the natural rock phosphate. Its stock is about one billion tons. However, inspite of the existence of this huge amounts, no study has been done on the possibility of using this raw material as P-source for acidic soils, which covers more than 7% of Syrian agricultural areas. These areas are located in the humid and semi-humid regions and severely suffering from phosphorus deficiency. Powdered or dust natural rock phosphate were added to the soils at different rates (700, 1400, 2100 kg ha-1) and compared with Triple Super Phosphate (TSP) as control. Rye Grass was used as a test plant. P content in plants was determined after each cut. Phosphorus absorbed by ray grass plants was maximum by using natural rock phosphate compared with dust phosphate and control. Moreover, the available amounts of residual P2O5 in the soil after harvest give enough stock to the following crop. The addition of natural rock phosphate increased the soil pH with different values depending on kind and rate of the added phosphates, while the TSP reduced it.