Fossil insects found and collected at a site in Kasugai City, Aichi Prefecture, Japan were investigated and classified for a study involving the reconstruction of palaeoenvironmental conditions of the area. The deposit containing a total of 4,179 specimens can be divided into 11 parts, each of which can be considered as the real specimen belonging to the corresponding period, from the Middle Jomon to the late Edo periods. As a result, palaeoenvironmental conditions of such areas through Middle Jomon to Late Edo can be explained as follows: there were many forests and inhabitants living in woodlands in the Jomon period; the numbers of aquatic insects increased in the Yayoi period and many paddy fields were opened and cultivated; in the Nara period the area was converted to a natural lowland; paddy fields appear again in the Heian period; and in the Edo period, taxa of insects living in the vicinity of human dwellings are thought to have increased considerably.