Abstract: 【Objective】In order to improve the detection of low abundance proteins in plant leaves, the effective extraction methods were established in poplar leaves for proteomics analysis.【Method】 Trichloroacetic acid(TCA)-acetone coupled with polyethylene glycol(PEG)fractionation and sodium dodecyl sulfate(SDS)-phenol coupled with PEG fractionation were evaluated, combined with SDS-polyacrylamide gel electrophoresis(SDS-PAGE)and two-dimensional electrophoresis(2-DE).【Result】The SDS-PAGE results showed that TCA-acetone coupled with PEG fractionation is superior to SDS-phenol coupled with the PEG fractionation method. Further, proteins with PEG fractionation and no PEG fractionation coupled with TCA-acetone were compared by using 2-DE, and the gel maps displayed that PEG fractionation is a good way to deplete the Rubiscos and improve the detection of low abundant proteins. The PEG fractionation method can detect nearly 90 more spots than nonfractionation can. 【Conclusion】LTQ-Orbitrap XL was used to identify several proteins from the PEG fractionation coupled with TCA-acetone. The TCA-acetone coupled with PEG fractionation is an effective approach for the detection of 2-DE analysis and mass spectroscopy(MS)identification of lower abundance proteins.