This paper presents a case study of canal-side settlements in greater Bangkok, which focussed on canal-side settlements transformed by modernization over a period of time. Three different sets of data. every twenty years in the years 1952, 1974 and 1998 compiled through the aerial photographic interpretation technique were examined, and a survey research and field survey were undertaken. The paper examined two levels in the study for the purpose of (1) the analysis of-settlement structure (fabric pattern of settlement) (2) the analysis of change in building types from old types to new types. First, the settlement structure has changed by sites which are related to space, canals, roads, land sub-divisions, and-site patterns in different locations in greater Bangkok. Second, changes in building construction type occurred and dwellings were built in modem styles and materials. Moreover. those changes of building types are correlated with the changing in settlement structures in the same way. The transformation process of house forms indicated change from a traditional to a modern type, which took over forty years in Bangkhu Wiang (urban-fringe), Klong 9-10 and Sai Gong Din (suburb area). Meanwhile the process took twenty years in Mahasawat (urban-fringe) since it was the nearest to the CBD.