Primary concern of this paper is kampongverbetering (kampong improvement in Dutch East Indies), which was to have significant influence on postcolonial improvement. Major findings in this paper consist of following points. 1. Examination into the kampongverbetering implemented in Dutch East Indies reveals that postcolonial improvement known as KIP apparently owes its basic ideas to its predecessor. 2. Accomplishments of kampongverbetering supervised by the central government show close resemblance to the items prescribed by detailplan, which was the forthcoming driving force of the contemporary city-planning act. 3. Kampong Sidodadi, one of the first kampongs improved in Surabaya in 1929,turns out to be still inhabited by Madurese as it was in the colonial period despite constant change of the residents. 4. Observance of building lines in Sidodadi had been closely related to the drainage gutters installed both in colonial and post colonial period.