Update information Late blight disease (LBD) caused by the pathogen Phytophthora infestans (PI) is the most devastating disease limiting potato production globally. To better understand potato molecular response to LBD, the proteomics and morphological changes of three potato cultivars: Favorita (FA), Mira (MA), and E-malingshu N0.14 (E14) was investigated 5 days after PI inoculation, using iTRAQ-based method. Proteomic analysis of the cultivars resulted in the identification and quantification of a total of 3306 and 2044 proteins. Cluster analysis revealed MA and E14 clustered together separately from FA. Protein expression pattern and related functions revealed the cultivars shared a typical hypersensitive response to PI, including induction of elicitors, oxidative burst, and suppression of photosynthesis. Meanwhile, MA and E14 deployed additional specific responses different from FA, involving high induction of protease inhibitors, serine/threonine kinases, terpenoid, and polyketides, hormone signaling, and transport, which contributed to MA tolerance of LBD. Furthermore, the induction of pathogenesis-related proteins, LRR receptor-like kinases, mitogen-activated protein kinase, WRKY transcription factors, jasmonic acid, and phenolic compounds mediate E14 resistance against LBD. These proteins were confirmed at the transcription level by qPCR and at the translation level by western-blot. Our results provide further insights into the different potato proteomic defense machinery against LBD.