Wheat (Triticum aestivum L.) yellow rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive diseases of wheat worldwide. To clarify the molecular details and components of the resistance response in wheat offers further possibilities to combat yellow rust. In this study, differentially regulated early response proteins in wheat leaves infected by Pst isolates were investigated by proteomic approaches. Total proteins extracts from leaves harvested at 24 hour post inoculation (hpi) were separated by two dimensional liquid chromatography system, ProteomeLab PF2D. Following PF2D analysis, six hundred and thirty-seven protein peaks were compared one by one between protein patterns obtained from pathogen-and mock-inoculated leaf tissue. Among those differentially expressed 33 proteins were identified in Pst-infected plants as compared with mock-inoculated controls by nanoLC-ESI-MS/MS. Six proteins were exhibited homology to fungal proteins. Two fungal proteins, including E3 ubiquitin protein ligase and Ubiquitin-like protein, are important members of ubiquitin-proteasome system which the importance of the its proteolytic function in regulating the virulence of pathogenic fungi has just been realized recently. Other identified 27 proteins were host proteins in response to Pst and classified in five groups based on their roles in diverse biological processes. The results indicated that identified defence related proteins such as pathogene related protein 1 and 4 (PR1, PR4), Glutathione S transferase (GST) are major component for systemic acquired resistance (SAR) which is one of the strong disease resistance form in plants and appears within several days following the initial pathogen attack.