Urban internal structure can be regarded as the spatial reflection of social and economic activities in urban area. According to the model of spatial changes of population and economic activities, the process of urbanization can be divided into three stages: typical urbanization stage in which agglomeration is the main power, initial suburbanization stage in which agglomeration and dispersion are also important, and typical suburbanziation stage in which dispersion is the dominant character. Accompanied with these urbanization stages there are three types of urban internal structure: one center and mixed land-use pattern, transformation pattern from one center to multiple nucleus and multiple nucleus, specialized land-use pattern.Dalian City was selected as a case in this paper, and the land-use maps of 1980 and 1989 were collected. According to the land-use patterns in different periods, the urban area can be divided into three zones. After discussing the transformation of land-use structure of Dalian City since the 1980’ s by analyzing the changes of the degree of mixed land-use in every zone, the model of urban internal structure for Dalian City is summarized. The conclusion is that Dalian City is in a transitional period of urban internal structure, and suburbanization in Dalian City is the result of the urban internal structure’s transformation.