Human mobility is, by some authers, said to be one of the main couses of pesonal and social disorganization, or of social and cultural changes, at least indices of their causes as Burgess once said. But migration, a most important factor of such mobility, has been studied chiefly on place of birth data or net migrators, not on all cases of migration in a given cmmunity, which took place actually in a certain time, that is to say, not as a kind of spatial mobility. This is perhaps owing to the fact that we have no such rigid official registration system of migration as those of birth and death. However the data that can de obtained from our rationing system of stable food that has been taking effect in and after the second War in Japan, are, if used with proper discretion, to offer us adequate information on some attributes of all migrators. The data of this research were, therefore, taken from the official registers of this system kept in a city called “Yokkaichi” situated on the west coast of “Ise Bay”, about 40 k.m. south-west of Nagoya. It is a port city of the middle-class type, chiefly industrial, with a population of about 130, 000. They were limited to all of those who migrated in or out in a year, 1951. The number of migrators studied is about three million. <BR>The data were arranged according to the two districts, the central older district and the outer new one, and further divided into 15 areas, 7 of which were in the former district and the other 8 of which were in the latter. And they were analyzed on the viewpoints of migration rate, sex ratio and age distribution of migrators, and distance traversed by them. Thus the migration patterns of two districts and 15 areas were compared. As the result we have had the following tentative conclusions so far. Of course we must acknowledge some serious exceptions. (1) The more urban, namely, the more indusrial or/and commercial an area is, the higher the migration rate of that area is. Therefore, mobility is thought to be closely correlated with urban characteristics. (2) Two distinct polar types can be discerned among the migration patterns of districts and areas. The one is that migration selectivity on age and sex is more severe or stronger and the number of migrators who went longer distance is far larger than that of those who did shorter distance. The other is that selectivity on both is rather weak and shorter-distance migrators are more numerious than those who migrated longer distance. (3) The former type is, generally speaking, found in the district and the areas which are industrial rather than commercial or more, industrial, especially in the areas in which a certain kind of industry prevails predominantly. The latter one is found in the district and the areas which are distinctly commercial or more commercial. So it can be assumed that industry in general is rather, or perhaps some kinds of industry are largely, correlated with migration selectivity.