Abstract: <FONT face=Verdana>A rapid method for determination of available phosphorus in calcium superphosphate with disodium ethylene diamine tetraacetate (EDTA) as extracting solution was studied.Influences of dosage of extracting solution,extraction temperature,and extraction time on extrating rate of available phosphorus were investigated and quinoline phosphomolybdate volumetric method was adopted to analyze the content of phosphorus.Research results showed that available phosphorus in 1 g calcium superphosphate sample can fully be extracted with 100 mL EDTA solution (37.5 g/L) oscillating in water bath for 10 min at 80 ℃±1 ℃;determination results of this method accorded with those measured by the standard method,Determination of Available Phosphorus in Calcium Superphosphate,GB 20413—2006 and absolute deviation was less than 0.20%;precision test results showed that the relative standard deviation was less than 0.5%;additionally,analysis time of the new method reduced by at least 2.5 h comparing with the standard method.This method not only has high accuracy and precision,but also shortens the measurement time.Therefore,it is a rapid,simple,and accurate analysis method which is able to totally meet the field production analytical requirements.</FONT>