Abstract: Objective To evaluate the role of insulin-like growth factor binding protein-2(IGFBP-2) in the diagnosis for early stage rectal cancer. Methods The patients with early stage rectal cancer (n=84),age and sex matched patients with benign rectal lesion (n=50) and healthy controls (n=32) were recruited.The serum IGFBP-2 was determined by enzyme-linked immunosorbent assay (ELISA).The levels of IGFBP-2 among the patients with different gender,age,invasive depth,differentiation grade,diameter and clinical stage were compared.Pearson correlation analysis was performed to study the correlation between serum IGFBP-2 and clinicopathological parameters.ROC curve analysis was used to assess the sensitivity and specificity of IGFBP-2 in the diagnosis stage 1 and 2 rectal cancer. Results The level of serum IGFBP-2 in early stage rectal cancer group,benign rectal lesion group and healthy control group were 223.7-360.9,158.2-199.6 and 135.6-184.5 ng/ml,respectively,the cancer group was significantly higher than the other two groups (P<0.05).There was no significant difference between the benign rectal disease group and control group.The serum IGFBP-2 levels was different between different invasion depth,T3-T4 rectal cancer was higher than T1-T2 cancer,in Mann-Whitney teat Z value was 2.28(P=0.02).The AUC for diagnosis pTNM Ⅰ phase cancer and pTNM Ⅱ phase cancer were 0.701 and 0.753,respectively.When IGFBP-2 short-cut process 197.33 ng/ml on diagnosis pTNM Ⅰ phase cancer,the sensitivity and specificity were 0.874 and 0.643,and on pTNM Ⅱ phase cancer the short-cu process 242.17 ng/ml,the sensitivity and specificity were 0.786 and 0.655. Conclusion The serum IGFBP-2 levels are significantly related to the degree of tissue differentiation,and will make a distinction between malignant pathological changes and benign lesion,the low diagnosis specificity limited the clinical application.