The invention discloses a method for serologically detecting Matrix metalloproteinase 11 (MMP11) and the application thereof. The gene chip technology and the bioinformatics method are adopted to obtain stomach cancer gene expression spectra, and by taking the MMP11 gene for example, the expression characteristics of the gene in the tumor cell lines and tissues are verified at the levels of mRNA and protein. At the same time, a detection kit for the MMP11serum is established by utilizing the technique of the enzyme linked immuno sorbent assay (ELISA), and the expression level of the MMP11 protein in the serum of stomach cancer patients is detected. The level of the MMP11 protein in the serum of stomach cancer patients is obviously higher than that of a non-cancer comparison group (p is lower than 0.001), and the same tendency is also found in the breast cancer, the colon cancer/rectum cancer and the lung cancer. In the serum detection to the stomach cancer patients, the sensitivity of the MMP11 is higher than that of a tumor molecule marker such as CEA, CA199, CA72.4, CA242, etc., and MMP11 and CA199 have good correlation (p is equal to 0.017). Through the analysis of the clinic pathological data, the level of the serum MMP11 has the obvious correlation (p is equal to 0.009) with the cancerometastasis state of the stomach cancer patients. The MMP11 is possible to become a novel tumor serum marker for the diagnosis and the prognostic judgement of the tumors.