Abstract: As the regional background and cooperation in tourism，there is an eccentric symbiotic relationship in Qinghai-Tibet regional tourism. This paper introduces the theory of population ecology’ssymbiosis to assess the symbiotic relationship between the regions in QinghaiTibet area from the quantitative angle. The results show as follows: (1) There is a positive correlation between the Qinghai-Tibet two symbiotic units in the main qualitative parameters, symbiotic degrees characteristics of the two units are “+”, which shows the symbiotic relationship between Qinghai and Tibet two symbiotic units; (2) The average symbiosis characteristics of foreign exchange earnings from symbiosis unit tourism are respectively δSab= 4.085 86,δSba= 0.494 154, the average characteristics of the degrees of the symbiotic tourist arrivals are respectivelyδRab= 3.638 348,δRba= 0.419 36,δSab(δRab) ≠ δSba(δRba)> 0, showing Qinghai and Tibet are two positive elements in the asymmetrical symbiosis; (3) The average of the main quality parameters of the symbiotic unit coefficient is θSa (0.833 005) + θSb (0.166 995) = 1, θRa (0.824 318) + θRb (0.175 682) = 1, which is consistent with characteristics of symbiosis symbiotic coefficient and the degree of “1”. However, 0.5 <θSa (θRa) <1, which shows Qinghai impacts Tibet a lot in tourism, on the contrary, Tibet impacts Qinghai less. The result shows that the cultural and geographical units in Qinghai-Tibet are closely related to inbound tourism, and there is a symbiotic relationship. This study provides new research ideas in a new perspective for regional tourism cooperation and has a great practical significance for Qinghai-Tibet regional tourism management and local economic development

Key words: symbiosis, the QinghaiTibet area, regional cooperation, inbound tourism