About 70 years have passed since the end of World War II. The state of Japanese land use has much changed from being completely ruined to very advanced with highway and Shinkansen (Express Railway) networks, the productive Pacific Coast industrial districts and the Tokaido Megalopolis from the World City Tokyo to Osaka via Nagoya. In this change the National Land Development Policy of Japanese Government has played an important role. The Policy constituted of seven National Land Development plans, such as The Development Plan for Specific Regions settled in 1950, the First National Land Development Plan in 1962, the Second Plan in 1969, the Third Plan in 1977, the Fourth Plan in 1987 and the Fifth and last Plan called "The Ground Design of Japan's Land in the 21st Century" in 1998. This paper analyzes how these plans were influenced by factors such as the international & national socio-economic situations (1), the participation of the then Prime Ministers (2) and the social trend for thoughts on national land use (3), respectively. It also analyzes which were the most important aims in constructing the spatial structure of the nation (1), to promote the socio-economic conditions of individual region (2), or to control the natural environment (3), respectively. This analysis is based on the book titled "The Testimony on the National Land Policies after World War II in Japan" (Sengo Kokudo-Keikaku no Shogen) writen by Atushi Simokobe who had been the main player in making most of the plans and my experiences as one of members of the National Land Development Plan's Council in twelve years. In my analysis, the Plan for Specific Areas and the first Plan were introduced for reconstruction and the growth of industries such as agriculture, coal, electric power, iron & steel, and petrochemicals. The second plan aimed to create the National Spatial Structure for the 21st century by constructing a high speed traffic and communication network in all over the country. This strategy has continued for about thirty years during the third, fourth and fifth plans while being revised. The third plan covered the weak points of the strategy by focusing on dwellings and the natural environment. The fourth plan aimed to weaken the Tokyo One Polar Spatial Structure and promote a multi-polar one by strengthening central management functions in other big cities. The fifth plan aimed to weaken the regional disparities by constructing several National and Local Axis in the northern, south western part and area along the Japan Sea which are periphery regions in the country. The change of strategy in the National Land Development Policy from promoting industries to creating a National Spatial Structure from the second plan occurred by the establishment of a bureaucratic system for making plans and Dr. Simokobe initiative in this system.