This work proposes a method to assess the molecular profile of perioperative circulating tumor cells in peripheral blood (PB) of colorectal cancer patients for differentiating the dissemination process of tumor cells. Two-point quantification of multiple marker genes was designed for describing the profile. The expression levels of cytokeratin 20 (CK20),carcino-embryonic antigen (CEA) and survivin mRNA in PB and tumor tissue samples in 37 colorectal cancer patients from 1 d pre-operation to 2 h postoperation were detected with real-time quantitative reverse transcription-polymerase chain reaction. β-Actin mRNA was used as internal control to standardize the results of different mRNA expression levels. The data analysis using Stata statistical packages,Chi-Square test and Mann-Whitney test indicated the expression level of CEA mRNA in PB increased significantly,while those of CK20 and survivin mRNA decreased significantly. Quantitative comparison with tumor tissues indicated that the increase of CEA mRNA level in PB coincided with the decrease of CK20 and survivin mRNA levels in different tumor cells. These results showed surgical manipulation caused tumor cells shedding into blood from primary tumor tissue and significant increase of CEA mRNA level,while occult tumor cells with high expression levels of CK20 and survivin mRNA before surgery decreased after surgery. This work proposes a method to assess the molecular profile of perioperative circulating tumor cells in peripheral blood (PB) of colorectal cancer patients for differentiating the dissemination process of tumor cells. Two-point quantification of multiple marker genes was designed for describing the profile. The Expression levels of cytokeratin 20 (CK20), carcino-embryonic antigen (CEA) and survivin mRNA in PB and tumor tissue samples in 37 colorectal cancer patients from 1 d pre-operation to 2 h postoperation were detected with real-time quantitative reverse transcription- The data analysis using Stata statistical packages, Chi-Square test and Mann-Whitney test indicated the expression level of CEA mRNA in PB increased significantly, while those of CK20 and survivin mRNA decreased significantly. Quantitative comparison with tumor tissues indicated that the i ncrease of CEA mRNA level in PB coincided with the decrease of CK20 and survivin mRNA levels in different tumor cells. These results showed surgical manipulation of tumor cells shedding into blood from primary tumor tissue and significant increase of CEA mRNA levels, while occult tumor cells with high expression levels of CK20 and survivin mRNA before surgery decreased after surgery.