This investigation was carried out to study the optimum length of nutrition surveys and the daily variations of nutrient intakes on 59 students' families in a women's college. The daily average nutrient intake did not vary as the number of days surveyed increased to a maximum of 7 days. The mean caloric intakes of over 4 days were about the same as that of 7 days. The mean intakes of protein and vitamin B1 for 5 days were almost equal to those of 7 days. Five families were randomly selected to observe their daily variations of nutrient intakes from the whole households. It was found that each nutrient intake seems to have greater daily variation than these in the whole group studied, and that the longer period of survey might be needed to make a proper estimation of nutritional intakes.