Abstract: Ultrafine grinding activations of phosphate rock and their dynamic phosphorus releasing rates were investigated by using the vibration mill wet grinding processing method in which the inorganic activator and organic activator were added. The results show that the milling efficiencies are significantly improved, and the milling periods are shortened by adding the activators in the processing. The available phosphorus contents of the phosphate rock are increased by using the ultrafine grinding activations. By adding the activators to superfine chollophanite powder and 2h superfine processing, the available phosphorus contents of the powders which are mixed with the inorganic activator, the organic activator, and the inorganic--organic activator combination are 1.82, 1.86 and 1.83 times higher than that of the chollophanite without any additions, respectively. The results of the continuous 2% citric acid extraction experiment indicate that the cumulative release amounts from chollophanite by the check (only milling) the three additions are 1.90, 1.86, 1.64 and 1.69 times higher than that from the raw chollophanite