Proteomics is the large-scale analysis of proteins, contributing for understanding of gene function. Functional genomics, proteomics, and even metabolomics are the footsteps of genomics that are useful tool to expand of our knowledge on the biological hierarchy of the transcription, translation, and production of small molecules. However, proteomics is a method for assessing the wide range of information such as the structure, expression, localization, biochemical activity, interactions, posttranslational modifications and cellular roles of proteins following protein isolation, digestion and mass spectrometry. Proteomics, as a significant post-genomic tool in the field of science, allows researchers to decipher underlying molecular mechanisms behind different metabolic pathways. Proteomics studies are mostly based on protein identification as using mainly bottom-up approaches such as DDA or MudPIT methods as examples of shotgun proteomics techniques. By using the high throughput mass spectrometer technology, huge output data of peptide spectra has been generated.