This paper discusses theoretically and methodologically the determination of city character in urban planning.City character signifies the major functions of a city and reflects the specialized role the city plays within a region or a country.City character,though being comparatively stable within a short period,may change with the development of the city,and therefore in urban planning the past and future character of city,i.e.historical and planing character,should be differentiated from the present character. It is pointed out that the assessment of city character should not only be based on the merits of city concerned,importantly,also based on various analysis,regional and economic structural.In addition,studying historical and regional development,comparing with other cities,and adopting qualitative and quantitative,all of those are very important. After a series of study,the authors bring out some problems still to should be solved.(1)the comparability of Chinese urban statistical data,(2)a convenient way to calculate the basic/non-basic ratio,and(3)a system of the intensity index of urban functions which can universally be applicable to all cities and urban functions.The intensity index of urban functions is a new concept introduced in this paper.