The dissolution kinetics of Florida and Jordan phosphate ore was studied in diluted nitric acid (0.2, 0.5, 1.0 mol.L-1), and in phosphoric acid (55 wt% H3PO4) aqueous solutions. It was found that the hydrogen ions concentration is a controlling factor, but the calcium ions concentration can not affect the dissolution rate in the range of 0.0 and 2.0 wt% Ca2+. The effects of temperature, stirring intensity and the size of ore particles were also investigated. The transfer of hydrogen ion depends on the diffusion, while the calcium ions transfer is assumed to be depended on mechanically stripping. The shrinking core model with hydrogen ions diffusion control match the experimental results.