The former administration office building of Kyeong-seong-bu(京城府) was a building converted from the Japanese residency-general's of Kyeong-seong(京城理事廳) which was originally built as the Japanese consulate in J oseon(日本領事館). It was too worn and too small as a Kyeong-seong-bu administration office even with several annexes. Kyeong-seong-bu tried to build a new big administration office building at the vacant north side of the same site, which was closely faced to the rotary in front of the Bank of J oseon(朝鮮銀行前廣場). But this trial was ended in vain due to insufficient budget. Therefore Kyeong-seong-bu built a new administration office building in another site and moved to it in 1926 with debts. For paying for the debts Kyeong-seong-bu sold the former site after partitioning with new roads through it. As a result the nature of the former site and its surroundings was changed. This study traces the changes and inquires how the authorities in the colonial J oseon and various commercial powers of Kyeong-seong-bu behaved for their own interests in the meantime. It makes use of the historical records and documentary literatures between early 1910s and early 1930s.