The differentially expressed proteins in soybean xylem sap after phenanthrene exposure were screened by the threshold (fold change≥1.5 for up-regulation or ≤ 0.67 for down-regulation, P<0.05). Peroxidase (A0A3B5XXD0) was significantly decreased after phenanthrene exposure (fold change≤0.67, P<0.05). But there were numerous and stable existents of peroxidase (A0A3B5XXD0) whether under phenanthrene exposure or not. The quantitative approach of the proteomic data analysis relied on the label-free quantification (LFQ) intensities calculated by MaxQuant.The large amount of peroxidase and the extraordinarily increased expression of uncharacterized protein under phenanthrene exposure led to promote the acropetal translocation of phenanthrene in wheat xylem sap.