The secreted proteins of Phytophthora infestans were separated by two-dimensional electrophoresis with immobilized pH (4~ 7, non-inear) gradients as the first dimension and SDS-PAGE as the second.The silver-stained proteins spots were analyzed by using PDQuest 7.1.0 software.850 detectable protein spots were detected on the 2D-gel.There were 257 proteins in the 0 ~ 25 kDa Molecular weight, 448 proteins in the 25 ~50 kDa, 128 proteins in the 50 ~75 kDa, and 17 proteins more than 75kDa.The isoelectric point of 317 proteins was 4 ~ 5, 363 proteins was 5 ~ 6, and 170 proteins was 6 ~7.By MALDI-TOF mass spectrometry analysis and Mascot database searching, 13 protein spots were screened.Among those proteins, NPP1 (Necrosis-inducing Phytophthora) protein of P.infestans were detected.The NPP1 published protein sequences of P.infestans was analyzed, the signal peptide was predicted by SignalP v3.0 and PSORT, the transmembrane helix was predicted by TMHMM-2.0 and THUMBUP, the big-PI Predictor was used to predicted GPI-anchoring site, and subcellular protein location distribution was analyzed by TargetP v1.01.The resultes showed that the NPP1 protein was secreted protein with signal peptide, the signal peptide was composed by 19 amino acid.the NPP1s Molecular weight was 25518.2 Da, and the isoelectric point was 5.27.