In order to explore changes in accessibility and connectivity of urban traffic network before and after the construction of subway,traffic networks within the Second Ring road,Hohhot,was analyzed based on complex network theory.Firstly,the urban road traffic network and the urban compound traffic network with the adjunction of the subway to former were mapped.Secondly,the node degree,clustering coefficient,average path length and node strength of the two networks were calculated based on Supe rMap.Finally,the values obtained above were compared and analyzed.Results show that both of the two traffic networks have some characteristics of small clustering coefficient reflected in random network and scale-free network.The latter,compared to the former,network diameter and average shortest path reduce,the average node degree and average node intensity increase.That is to say,with the adjunction of the subway,the connectivity and the accessibility of the entire network are significantly improved,and its carrying capacity increases remarkably.