Abstract: [Objective] The effect of different pretreatment on the test results was investigated, in order to determinate phosphorus in plants rapidly and accurately. [Method] Four factors such as accuracy, precision, reagent consumption and the time spent were compared to obtain advantages and disadvantages among three kinds of methods. [Result] The result error were respectively -0.12～0.05 and -0.19～0.01 with the pretreatment of microwave and wet digestion, when standard materials of plant GBW10049, GBW10048 and GBW07603 were taken as the reference objects. However, the determination result was low by using dry digestion with the relative error of 8.2%. Moreover, the recoveries of the phosphorus from plants were between102.3 % and 108.3%, and the relative standard deviation (RSD) was lower 4.4% when microwave digestion was applied. Factors affecting the spectroscopic properties were discussed, finally 20 min was chosen as color time. Under optimum conditions, good linearity was exhibited from 0.1 to 1.0 μg/mL with correlation coefficient of higher than 0.9990. [Conclusion] The method was successfully applied for the analysis of phosphorus in real plants samples.