The surveys on the Japanese National Character is a repeated social survey project that the Institute of Statistical Mathematics has conducted since 1953. It is a series of repeated cross-sectional surveys, in which nationwide survey has been conducted every five years by the same sampling procedures, by the same survey mode (face-to-face interviewing), and with basically the same questionnaire. The questionnaire consists of items covering broad topics in daily life, which intend to measure attitudes and opinions that might characterize “Japanese ways of thinking”. This project has the longest history among longitudinal nationwide surveys in Japan, and has maintained three basic aims: (1) Elucidation of the Japanese "National Character", (2) Research on survey methodology, and (3) Development of techniques of statistical analysis. This paper intends to introduce the outline of the project, by exemplifying a few typical items which record long-term changes of Japanese opinions, and emphasizes the importance of continuity of the project. We also refer to one of the typical results from the 13th nationwide survey conducted in autumn of 2013. Besides, we discuss the future prospects of this survey project.