Update information. Colorectal cancer is the 3rd commonly diagnosed cancer (10.2%) and 2nd cause of cancer death (9.2%) in all cancers.There will be estimated 1.8 million new colorectal cancer cases and 0.9 million colorectal cancer deaths in 20181. As the 5th incidence rates and mortality rates cancer in china, colorectal cancer incidence rates has increased from 1990 to 20112,3. CRC is concidered as a muti-step progress diseases4, patients with precursors lesions and early stage CRC can get great benefit from surgical treatment, colonoscope can detect visiable early dieases but not suitable for large-scale screening5, because of the poor sensitivity or specificity, blood carcinoembryonic antigen(CEA)6,7 and fecal blood testing(FOBT)8 provide limited help. There is no standard biomarker predicting CRC lymph node and liver metastasis4, although It’s very valuable for patients and docter before and after surgery9. Liver is the main site for colorectal cancer metastasis10, hepatic resection is the only treatment and successful for CRC-LM11, Unfortunately, over 50% of patients who get hepatic resection develop recurrences11, since then it’s hlepful to find biomarkers for monitoring CRC metastasis, blood CEA has been accepted as indicator of CRC progress12, in current study, we aim to explore a more convient and presion way for monitoring CRC metastasis.