Abstract: Twenty cases of early colonic carcinoma were reported. The clinical symptoms and X-ray features revealed in double contrast examination of these cases were analysed. It was pointed out that the good quality of the X-ray films of the sigmoid colon and rectum was very important for detecting early colonic carcimoma. Whether the lesion has a pedicle or not could not be regarded as a differential point for the malignant and benign lesions. However the size, height, shape and the base condition of the lesions were of great significance in the differentiation between malignant and benign tumor. The endoscope and double contrast examination of colon had their own advantages and disadvantages, and should be cooperated and complemented closely with each other. A(?)cording to the authors experience in this series, the diagnostic and differential principles for the early carcinoma of the colon were presented.