Amine-specific isobaric tagging (iTRAQ) reagents, as a new class of isobaric reagent, were developed in 2004, which, combined with liquid chromatography and tandem mass spectrometry (LC-MS/MS) , have been applied to the identification and quantification of proteins in a wide range of biological samples, including bacteria, yeasts, human tissues, cells, and fluids. As a new method of quantitative proteomics, the technique of iTRAQ allows for the quantitative analysis of four samples simultaneously and displays its advantages of high-flux, food reproducibility, and high sensitivity; it also provides a potential technological platform for studying the mechanisms of the development and progression of prostate cancer.