Different from research on a single ancient Town,this research choses 2 typical examples,which were the "organic" Ancient Town of Hongjiang located in the south mountain area,and the "regular" Ancient Town of Pingyao located in the north plain and planned under the theory of Kaogongji,and compared their city form on 2 levels,which were their material form and sociological characteristics behind.Through surveys,collecting documents,analyzing and summing up the fundamental information,it is discovered they are different in such aspects of their material form as the relation between town and natural environment,plan form of town,most important building type,building shape,relation among building units,relation between border zone and river in the vicinity,and the outer material differences originate from their different sociological characteristics including urban origins,urban functions,urban population make-up,urban developing rules,starting points and development of culture.