Background: Many studies found positive relationship of inflammation-based markers and cancers prognosis. However, this relationship was hardly clarified in geriatric cancers. This study aimed to distinguish some inflammation plasma factors which might become prognostic and predictive markers in the elderly patients with metastatic colorectal cancer(MCRC). Methods: Patients of age > 65 with MCRC, given palliative chemotherapy and targeted therapy at our institution from January 1^st 2004 to October 1^st 2015, were identified. The impact of some inflammation plasma factors on patients’ survival and chemotherapy efficacy were analyzed, including carcino embryonie antigen(CEA), carbohydrate antigen 19-9(CA 19-9), lactate dehydrogenase(LDH), C reactive protein(CRP) and the neutrophil-to-lymphocyte ratio(NLR). Other important clinicopathologic factors for prognosis, such as clinical stage, pathological grade, primary tumor sites, metastasis sites and different chemotherapy were contained in multivariate analysis. Results: The total of 270 patients with 2053 cycles of chemotherapy (mean cycles of 7.6), were followed up from five to 119.5 months(median 22.6 months). Median progression-free survival(PFS) for first-line chemotherapy was 8.4 months(95%CI 6.7-10.2 months) and median overall survival(OS) 32.62 months. (95%CI 25.6-35.8 months). OS significantly reduced in the groups of CEA ≥ 23ng/mL(P= 0.042), LDH ≥ 400U/L(P= 0.015), CA199 ≥ 37U/ml (P< 0.001), CRP ≥ 8.2mg/L(P= 0.003) and NLR ≥ 2.1(P= 0.022). Even when many important clinicopathologic factors were included in multivariate analysis, both CA199(RR 1.539, 95%CI 1.029-2.462, P= 0.036) and CRP(RR 1.631, 95% 1.081-2.462, P= 0.020) were still independent prognostic factors for OS. CEA ≥ 23ng/ml group had remarkable short PFS(P= 0.02), which(RR 2.552, 95%CI 1.283-5.078, P= 0.008) was also an independent prognostic factor in multivariate analysis. There was no relation found between ORR or DCR and any inflammation factor. Conclusions: In the elderly patients with MCRC, our study suggested abnormal increase in CA19-9 and CRP were independent prognostic factors for OS, and CEA was an independent predictive factor of PFS.