Objective To investigate the clinical value of conventional plain and contrastenhanced MR imaging, diffusion-weighted imaging (DWI) and magnetic resonance colonography (MRC) in the diagnosis of colorectal cancer. Methods 30 patients with colon cancer were included, including 19 males and 11 females, aged from 42 to 76 years with a mean of 54 years. The diagnosis in all patients was confirmed by surgical or biopsy pathology. All patients underwent conventional plain and contrast-enhanced imaging, diffusion-weighted imaging (b value=800 s/mm2 ) after colon cleaning and magnetic resonance colonography. The detection of colorectal lesion detail, disease extent and metastases by each imaging technique was compared. Results In 30 patients with colorectal cancer, lesions in 26 patients showed moderate signal intensity on T1- weighted imaging, 23 showed moderate or slightly high signal intensity on T2-weighed imaging, 24 had marked enhancement. Adjacent fat infiltration was found in 8 patients. 2 patents had surrounding organ involvement. 3 patients had lymph node metastasis, and 3 had liver metastasis. The lesion in 30 patients showed high signal intensity on DWI. MR colonography was performed in 11 patients, with success in six of them, where the stenosis extent of involved colon was clearly displayed. The detection rate of colon lesions was highest with DWI than whether T1- or T2-weighted imaging or contrast-enhanced T1-weighted imaging. Conclusion The combined use of multi-parametric MR imaging can clearly delineate the disease details and adjacent involvement of colorectal cancer． There are of highly clinical value in the diagnosis, staging and assessment of resectability of colorectal cancer.