Objective:To explore the scintigraphy of CGRRAGGSC labeled with 99mTc in nude mice bearing human breast cancer MCF-7. Methods: The CGRRAGGSC peptide was labeled with 99mTc using DTPA as a bifunctional chelator. Paper chromatography method was used to calculate the labeling rate and detect the stability. Immunofluorescence staining was used to evaluate the binding status of CGRRAGGSC peptide to human breast cancer cell. SPECT static scintigraphy at 0,0.5,1.0,2.0,3.0,4.0 h was performed in nude mice bearing human breast cancer after intratumoral injection of 1.85MBq/0.05 mL 99mTc-DTPA-CGRRAGGSC,99mTcO-4 and 99mTcO-4+DTPA-CGRRAGGSC,respectively. Immunohistochemistry assay was performed to observe the IL-11Rα protein levels in breast cancer. Results:99mTc-DTPA-CGRRAGGSC was radiolabeled successfully,the labeling rate was over 95% and the radiochemical purity in PBS and serum both were over 90% after 12 h at 37℃. Human breast cancer cells showed high binding abilities to CGRRAGGSC peptide. The scintigraphy showed that radioativity still deposited in tumor tissue at 4 h after intratumoral injection of 99mTc-DTPA-CGRRAGGSC,but radioactivity had faded obviously at 0.5 h after intratumoral injection of 99mTcO-4 or 99mTcO-4+DTPA-CGRRAGGSC. Breast cancer tissue had a higher expression of IL-11Rα. Conclusion:99mTc-DTPA-CGRRAGGSC can target the tumor tissue in nude mice bearing human breast cancer MCF-7,which lays a foundation for further study on the targeting therapeutic effect of therapeutic radionuclides rabeling CGRRAGGSC on breast cancer with expression of IL-11Rα.