Abstract: After the sample is decomposed with aqua regia, the determination of phosphorus content in the sample solution inductively coupled plasma atomic emission spectrometry is carried out. Through experiments the analysis conditions such as the matrix interference, acidity, enhancement of amount of samples, gas velocity of atomization, power, height of observation, analytical spectral lines are determined. The results show that the interference of iron, sample matrix of elemental iron does not affect the determination of phosphorus content. In the P 178.222 nm line determination, the detection limit was P 0.0006% ( corresponding to 0.1 g of sample, in a constant volume of 100 mL), the relative standard deviation was 3.14%～6.04% (n=11), the rates of spiked recovery were 92%～110%. The results of the determination of phosphorus content in the sample by this method accorded with the results of photometric determination.