抄録
1) It has been defined that the insula is a three to four story building in fairy large size, with shops on a ground level and rented to the public, as a rental apartment house. In one hand the definition mentioned above is acceptable according to researches and studies having been done in the past, but otherhand we should reconsider insula more widely according to the new criteria based on of their architectural quality and size. 2) The number of <<insula>> is shown as 46, 000 on the Regionaries, a precious ancient record. However a conflict is occured on their number of existed units, if we define <<insula>> as a rental apartment according to the old criteria of <insula>, the documents mentioned abobe the regionaries, therefor <<insula>> should be defined differently from <insula> by the reason mentioned above and we could guess there might had been some provisions in the Roman cities for their own on using the term of insula. At present, the number shown as 46, 000 might be indicating that of the gates facing to streets on a ground level.
