Experimental studies in vitro of the influence of X-ray irradiation on decomposing action of the glycerol extract of alkaline glycerophosphatase and arginase derived from the tissues of cervical cancer of the uterus and the musclature of the healthy uterine fundus have been attempted and the results obtained were reported as follows : 1. It has been shown that the cancerous tissue of cervic uteri contained more phosphoric acid and urea than the musclature of the normal fundus uteri. 2. It was found that the action of alkaline phosphatase and arginase of the uterine cancer tissue demonstrated stronger action than those of the tissue of fundus uteri. 3. Decomposing action of alkaline glycerophosphatase and arginase of the cancerous tissue of cervix uteri and the musclature of fundus could be suppressed when the enzymic extracts were irradiated and its effect was most pronounced with 300 r irradiation dosage. 4. Suppressing action of the alkaline glycerophosphatase when irradiated with X ray on the enzymic extracts of uterine carcinomatous tissue and fundus musclature, the malignant tissue would be more effective than the normal muscle tissue, while, the suppressing effect of the arginase, irradiated effect on enzymic extracts showed variation according to the dosage, but with 300 r, the effect was far more on the enzymic extract of the cancerous tissue.