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Colorectal cancer (CRC) is one of the most prevalent and deadly cancers, with an annual incidence of 1 million new cases. In 2012, around the world, there were about 693,000 deaths from colorectal cancer, which accounts for 8% of all cancer deaths, making it the fourth leading cause of cancer death, after lung cancer, liver cancer and stomach cancer. The development of new screening methods has become important due to an increasing incidence, as is the case for CRC. Advanced cancer has a poor survival, whereas when diagnosed at an early stage, survival is relatively good. Early detection will identify cancer when it is still localized and curable, preventing not only mortality, but also reducing morbidity and costs. The use of serum biomarkers as an indicator of disease in cancer screening programs could provide a promising alternative to existing methods. The aim of this study was to search and validation of peptide biomarkers specific for blood sera of patients with colorectal cancer. Samples that the first stage of work were used to identify the peptides were analyzed in SWATH mode, the spectra are taken while maintaining all other chromatographic (gradient, flow rate, column for separation) and mass spektromericheskih (parameters fragmentation, ionization source) parameters. Further, from the mass chromatograms were obtained extracted ion chromatograms MS / MS fragments for the entire library of peptides and integrated peak areas for the respective peptides were compared between different samples. According to the results of the statistical analysis revealed a number of peptides that were significantly different patterns of colorectal cancer from the control group. As a result of LC-MS/MS analysis of sera more than 6000 unique peptides originated from the almost 1000 unique proteins were identified. Using the method of SWATH we detected significant differences in content between the groups of control and colorectal cancer in 3 or more times.