Townhouse residential community makes people more comfortable for living,but we are facing the serious self-development phenomenon.Lots of self-development activities destroy the high-quality Townhouse residential community,greatly affect the comfort and unity of architectural styles,and seriously reduce the quality of living.And so on the developed country upscale from constructed the housing in Europe and America and Japan the development already to pass through the early exploration and the practice stage.But regarding our country, then just entered one from to raise spontaneously to the aware process.Although our country the upscale villa plan system gradually is enhancing now,but explained from the self-development phenomenon,overall speaking also has the disparity and the insufficiency.We take the Coastal Sunshine community of Dalian as an example in this paper.We get first-hand information regarding the illegal self-development through field research,surveys, in-depth interviews and other methods.Doing extensive and in-depth research on the concerned self-development activities and try to apply environment ethnology,get summary for the root cause of self-development from both designers and users levels.Take this as a starting point and figure out further way to upgrade the life quality of townhouse residential community. Compared to high-density residential areas,townhouse residential communities have more space for self-development,so the research has practical significance.Architects and planners in this regard should be more positive thinking,do their best to improve the life quality of the residents.