The Ainu are an aboriginal, illiterate people living in Hokkaido, southern Sakhalin and the southern part of Kurile Islands. Many old documents show that the Ainu in the Edo period (1603_??_1867) had exploited surrounding resources by fishing, hunting, and collecting and that they were migratory people.<br> The movement pattern of the Ainu in the Edo period has generally been recognized that they had migrated seasonally from the fixed home grounds. However, such general recognition was based on insufficient evidence. The aim of this paper is to examine whether the position of the Ainu's home ground was fixed or not in the Edo period and whether the members of the residential group of the home ground was stable or not.<br> The analysis of seasonal migration from the home ground was based on the document of Takeshiro Matsuura (1858). This document covers about 80 percent of all the numbers of houses and population (Table 2). The analysis of movement from the home ground was derived from tracing the names of heads of households in each settlement at intervals over a year. If the name of the head of household in settlement A in 1856 was found in settlement B in 1858, he and his family were recognized as having moved their home ground from A to B. The documents used in the analysis of stableness of residential groups are the lists of the inhabitants'names in 1856, 1858, 1864, 1865, 1866, 1868, 1869 and 1871. These were documented by the Japanese. The average number of houses per settlement was about 9 (Table 1). The study area consists of seven districts in Hokkaido (Fig. 1).<br> These analyses show that the home grounds of the Ainu in the Edo period had not always been fixed, and that the members of the home ground had not always been stable. The details of the findings are as follows.<br> (1) Seasonal migration from the home ground in 1858<br> Seasonal migration means that the Ainu migrate from the inland home grounds near rivers to the seaside for fishing in spring mainly under the management of the Japanese and they return to their home grounds in autumn. Most of the households had at least one seasonal migrant in 1858. The number of seasonal migrants differed in sex and age by district (Fig. 2 and Table 3). Most of the households had the remainders at the home ground and they probably lived there from spring to autumn (Fig. 3). This means that the position of the home ground did not change at least within a year.<br> (2) Movement of the home ground from 1856 to 1858<br> The smallest unit of movement from the home ground was a household. Twenty four percent of all households in seven districts moved their home grounds to other settlements from 1856 to 1858. While the Ainu moved almost within each of seven districts, the percentage of the moved households was different by district (Table 4). The settlement mentioned above was called mura and was composed of several small settlements called kotan in 1858 (Table 5) . In the Mitsuishi district, each settlement was composed of one small settlement, that is, mura was identical with kotan.In this district, the positions of the settlements were changed largely from 1856 to 1858 and the members of the settlement in 1858 were composed of households which had lived in different settlements in 1856 (Table 6). In the Shizunai district, some settlements were composed of a few small settlements in 1858. In this district, the positions of the settlements did not change so much from 1856 to 1858. Nevertheless, the members of settlement (mura) and of small settlement (kotan) in 1858 came from various settlements (Table 7). Similarly, the members of settlement and of small settlement changed in the Tokachi and Niikappu districts from 1856 to 1858.<br> (3) Movement of the home ground after 1858<br> In the Mitsuishi district, the movement from the home ground had continued after 1858.