Abstract: With the urban agglomerations as the growth poles of regions,the development of economic system of urban agglomeration is the circulation and interaction in the region. Therefore,it is important to compare those urban agglomerations with similar quality,history,construction,development orientation,etc.,in order to present some references. This paper chose the Guanzhong-Tianshui Economic Region Urban Agglomeration of northwest China and the Changsha-Zhuzhou-Xiangtan "3+5" Urban Agglomeration of central China(abbreviated to "Changzhutan") as the cases. The paper used the panel data regression to divide the economic development factors into three groups:common,dominant and others. Then,in order to enrich the theoretical thinking about the characteristics and the differentiation of the economic development under the background about "the balanced development of the central and western regions of China",the paper tried to use VAR,IRF and VD methods to analyze and compare the action intensity and features of each factor. The result showed as follows:Firstly,the degree of market development of Guanzhong-Tianshui was weaker than that of Changzhutan. And the regional economic momentum could be stronger when the market conditions improved. Secondly,the transport level of Changzhutan had gotten ahead of its current needs,and limited the development. With the economic environment and conditions improved,the limitation would vanish. Thirdly,science and technology promoted Guanzhong-Tianshui economic growth permanently. So,this urban cluster,maybe,could be built as the regional creative economic center. Finally,as the core power of Changzhutan,the secondary industry could not promote this region developing fast and permanently. And,this industry was not suit for the development strategy of ecological cities. Therefore, the industry structure needed to be restructured. Generally speaking,the paper used economic methods to compare the economic features of those two urban agglomerations,tried to discover the characteristics and models, and made up the gap that the individuality we just focused before. Therefore,this paper could give some interesting thoughts for requirement of "the Belt and Road Initiative" strategy.

Key words: influence factors, quantitative economy, inland urban agglomeration, One Belt and One Road, comparative analyze