Though voluminous literatures are available on urbanization and market gardening in the western suburbs of Tokyo, actual conditions have not yet been clearly explained with regard to the former farmers who gave up farming a few generations ago. The purposes of this study are to examine the way how the landownerships of agricultural lands have been changed, under urbanization, to present landownerships and to clarify the processes how built-up areas have been formed in previous farming land. The author analyzed the former farmers in Chuo 3 and 4 clime in Nakano-ku where the urbanization advanced rapidly since the Kanto Earthquake in 1923 and those in Musashino-shi which were gradually urbanized through the period extending from pre-war to post-war years. The following results were obtained from the analyses. In the case of Nakano-ku, farmers living there in the pre-war period transformed themselves into landowners who lent their own lands to city dwellers. However, the position of such landowners was weakened by the Ground and House Rent Control Act of 1939, and moreover the property tax introduced soon after the war was a great blow to them as it compelled them to decrease the lands they had owned before. Although they still held compratively large lots of land before the end of the 1950's, the enforcements of taxation in the 1960's, such as the real property tax, city planning tax, and especially, the inheritance tax, oppressed landowners and urged them to diminish and subdivide their estates. As a result, the lands for rent coverted from the former farmland by this process became a densely populated residential district. Same former farmers had large lots of land on which they could run high-rise apartment houses for rent, but most former farmers have small lands which are good only for constructing rooming houses and like. On the other hand, after World War II, in Musashino-shi where the urbanization had started with the development of munition plants in this area during the War, as in the case of Nakano-ku, there were some farmers who transformed themselves into landowners to lend their lands to city dwwllers, and at the same time, there were other farmers who did not lend their farmland to city dwellers, resisting the urbanization of the area even after the war. In the meantime, the farmers in this area sold the arable lands of their own little by little in the 1950's, restricting the supply intentionally to aim at the rise of land price. Based upon the Article Four of Farmland Act of 1952, they changed thier arable lands into urban land used for apartment houses, golf driving ranges, bathhouses, etc, in the 1960's and parking lots in the 1970's. Such practices of landowners naturally slowed down the pace of supplying lands to those who were in demand of them for residential purpose. Thus much open space was left untouched so that the densely populated situation as observed in akano could be avoided. As stated above, lands in cities have been continuously owned by traditional farming families from generation to generation, preserving “Rural Remnant” in a city. Those who have abondoned farming are engaged in special kinds of occupation such as gardeners, carpenters, and grocers. They also set up branch families on their land even after the urbanization. All these may be considered as the phenomena incidental to the “Remnant.” The time lag of urbanization between Nakano-ku and Musashino-shi caused the difference of the land supply system in the two cities, which again gave rise to the difference in the formation of bulit-up areas in those cities. In Nakano-ku the lands for rent mainly supplied by the conversion of farmland before the war brought about a high density of population, while in Musashino-shi the lands sold after the war caused the urban sprawl, and open space still remains here and there as parking lots and so on.