Clinical studies on 50 cases of Primary Hepatic Carcinoma ivere performed in the Department of Internal Medicine, Pusan National University Hospital over a period of 5 years from December 1go4 to October 19o9. The fo11owing results ivere obtained: 1, The serum alkaline phosphatase levels in primary hepatic carcinoma were elevated in 74o of cases, and ivere more zensitive than other liver function tests, The serum alkaline phosphatase JeveIs in primar y hepatic carcinoma seemed to be elevated in proportion to the size of the Jiver in the group of moderately enlarged livers, 3 The serum alkaline pho"hatase levels in primary hepatic carcinoma were more elevated in cases with metastases to other organs, 4, There was no apparent correlation betiveen the serum alkaline phosphatase levels and any of the other liver function tests in primary hepatic carcinoma 5. To summarize the above mentioned findings, elevation of the serum alkaline phosphatase was an important findings in primary hepatic carcinoma and the author emphasizes the diagnostic value of the serum a]kaline phosphatase level in detection of primary hepatic carcinoma.