Cross-border tourism region is a geographic unit which has large tourism development potential and complex management object, and becomes a new research focal point in tourism geography. Based on the Inter-Organizational Relationships (IORs) and social network theory, the paper indicates that the spatial cooperation behavior among cross-border tourism regions is essentially the network construction and reorganization of contacts and exchanges between the cross-border tourism organizations. Using the corresponding social network evaluating indicator system, the paper makes an empirical analysis for cross-border tourism region network structure and cross-border cooperation in the Tiantangzhai of Dabieshan, and then the conclusion is verified by core-periphery model. The results show that: (1) In terms of the network density, the whole Tiantangzhai network is smaller compared with the local network density, showing a weak tie between the administrative areas and a strong tie inside the administrative area, meanwhile structural holes are found. The network density between the low level administrative areas is bigger than that between the upper ones. The more cross-border dimensions are, the smaller the network density is. This reflects that there is a significant border effect in the cross-border tourism activity. (2) As to the network degree, the local degree is the biggest, followed by the global degree, and the border degree is the smallest. It is proved that tourism administrative region economy is an influential phenomenon. (3) According to Francisco's integrated model of IORs, the paper discovers that the cross-border tourism cooperation has transferred from a weak phase to a medium phase in Tiantangzhai. To enhance cooperation in Tiantangzhai cross-border region, concrete measures should be taken to achieve the aim of sustainable development by reducing the transactional costs, strengthening the conformity among departments concerned, building the good external environments, and setting up the cross-border tourism alliances.