This study was undertaken to elucidate effects of ingesting small or large amount of tap or iced water on circulation of normal healthy men with the purpose of furnishing basic data for nursing interven-tion of myocardial infarction patients. The subjects for this study were normal healthy men consisting of 30men and 30women in age from 22 to 30 years. One group consisting of 30men drank 240ml tap water on dayl and 240ml iced water 24hours later. The other group drank 960ml tap water on day 1 and 660ml iced water 24hours later. Blood pressure and heart rate were taken in a sitting position before ingesting water, and immediately after ingesting it and at 2,5,10,15,30 minute intervals thereafter. Changes of heart rate, systolic and diastolic blood pressure after ingesting water were compared with those of preingestive period. The results obtained were as follows: 1. There were no significant changes in blood pressure and heart rater after ingesting small amount of water regardless of its temperature. 2. No significant decrease in blood pressure after ingesting large amount of tap water at all time peroids was noted. 3. A strongly significant interaction effect between temperature and volume was demonstrated, that is, there was a highly significant decrease in blood pressure and heart rate at all time periods after ingesting large amount of iced water.