Abstract:To optimize the urban living environment,this paper presents an urban living environment evalua- tion model based on the method of principal component analysis. Taking Harbin for example, the living envi- ronment in Harbin from 1995 t0 2009 is studied, and the results show that from 1995 t0 2009, affected by the main components of the level of the green and education, social security, health service and food supply, the living environment has gone through two stages, namely the stage of improving significantly (1995-2003) and the stage of enveloping stably ( 2003-2009 ) . Finally, some appropriate suggestions for the improvement of liv- ing environment in Harbin are put forward