With the continuous economic development achieved since the end of the World War II, the Japanese life style has greatly changed Food consumption patterns. In this paper, I tried to find out some factors concerning the enlargement process of socialization of food consumption caused by the difference in life styles. As a basic aspect of empirical approach, it is necessary to study the difference in various life styles. Accordingly, the following two factors were used as analytical criteria: 1. The difference in labour styles by working hours, income and occupation. 2. The difference in life styles by time use, household organization and work pattern, such as: full and Part-time. The result of this study is as follows; The enlargement process of socialization of food consumption is caused basically by the differences in living patterns which were affected by the economic conditions. These conditions shortened working hours for food preparation by the substitution of socialization of food consumption, such as processed food, ready made food and take-out food. Additionally, a change from private-labour to social-labour is a general trend affected by social and economic development.