Abstract: Administrative boundary is one of the main factors of the cross-border tourism region space development. The border effect measure is the important yardstick to define its influence size. With indexes of social networks such as network density and centrality index, the paper constructs two types of measurement indicators which are the whole border effect and the node border effect, and also carries on empirical analysis for Dabie Mountain Tiantangzhai tourist area. The results showed that: ① The whole border effects of cross-provincial tourist areas are greater than that of cross-county tourist areas, the whole border effects on both sides of the same cross-border tourism region are also different; the proportion of significant node organizations of the cross-provincial border effect is higher than the cross-county border effect. And the non-significance nodes mainly concentrate on scenic area management committee, travel agency, scenic area business company and other social organizations. ② The border effect depends on the level of administrative boundaries, geographic traffic, tourism development level and maturity differences on both sides of the border, emotional, cognitive and other factors. ③ The source force of the cross-border tourist areas shielding effect into bridge effect comes from the symbiotic nature of tourism resources, the willing of stakeholders in the tourism market development, the fundamental force comes from the demand of regional tourism integration, and the corresponding transformation means are introduced. Based on social network the border effect analysis provides a new perspective for the study on cooperation mechanism of the cross-border tourism.