To (1) study the changing process of urban social life in Rattanakosin Island (2) study the present urban social life in the old area of Rattanakosin Island; and (3) propose appropriate procedure to develop and conserve the old Rattanakosin Island. The study reveals that the changing process of urban social life in Rattanakosin Island result from (1) such physical factors as the rapid expansion of urban area, the continuous development of inland transportation network, the land utilization and the architectural transformation (2) such economical factors as the trade liberation and the establishment of capitalism and (3) such social factors as the termination of feudal society, the abolition of slavery and the reformation of politics as well as social value; not to mention such external impacts as the westernization during World War and the great world economic recession, all of which have gradually brought about the changes to urban social life in Rattanakosin Island over time. The study is also well awareof the fairly close relationship between the current community dwellers, activities and space usage. However, insufficient knowledge and consideration on the urban living condition around Ratanakosin Island usually end up destroying the urban social life rather than developing and conserving it; and this will still be a concern in the years to come. The results from the study have led to the considerations that in order to successfully develop and conserve the urban way of life in Rattanakosin Island, it is recommended that the co-relation between the community dwellers, activities and space usage should be property maintained.