On the purpose of elucidating the malignant potential, flow cytometric DNA analyses were carried out using paraffin-embedded materials of 82 subserosal, serosal and adventitial invasive colorectal carcinoma. The ratio of DNA diploidy against DNA aneuploidy was one to two. DNA ploidy pattern was not correlated with histological grade but with histopathological factors such as lymphatic permeation, lymph node metastasis and venous invasion. At the primary operation, the rate of the liver metastasis in DNA aneuploid cancer was 16.4% but in DNA diploid cancer the liver metastasis was not observed at all. On the liver metastasis, the 5-year disease free survival rates were lower in patients with DNA aneuploidy (72.8%) than those with DNA diploidy (95.2%). These results indicate that DNA ploidy pattern is related to liver metastasis. Furthermore, the 5-year survival rates in patients with absolute curative resection were lower significantly in DNA aneuploidy (62.5%) than DNA diploidy (92.9%). In conclusion flow cytometric DNA analysis is useful for evaluating the biological malignant potential and predicting the liver metastasis in colorectal carcinoma.