Abstract: Urgency and important meaning on pretreatment of medium-and low-grade phosphate rock，as well as technical method species on pretreatment，present status，and existentially principal problems on pretreatment technology of medium- and low-grade phosphate rock in China were introduced.The basic process and merits of ammonium nitrate-nitric acid mixture- method in pretreatment technology of medium-and low-grade phosphate rock were put forward，thereby a feasible route for exploitation and utilization of medium-and low-grade phosphate rock was provided.At the meantime，continuation applica- tion meaning of ammonium nitrate-nitric acid mixture-method on phosphorus ore tailing was put forward. For more solving the problems of phosphorus resources depletion and environmental pollution etc.，a good development direction was found.

Key words: medium-and low-grade phosphate rock, ammonium nitrate-nitric acid mixture-method, pretreatment technology