With rapid introduction of exotic trees, natural habitat loss and landscape fragmentation were aggravated in mountainous areas. Construction of landscape eco-security pattern can provide feasible option to prevent landscape fragmentation and to protect natural habitats and biodiversity. Since 2003, a large amount of exotic tree species, Eucalyptus has been introduced into Lancang county of Yunnan province. The Eucalyptus replaced the native forest, farmland, wasteland and other ecosystems, leading to serious natural habitat loss, landscape fragmentation and biodiversity threatening. In this paper, the large areas in Lancang County of Yunnan Province, where Eucalyptus have been extensively introduced were selected as the case study sites to examine the landscape eco-security pattern for Eucalyptus introduction by using the minimum cumulative resistance model. The results indicated: (1) it's feasible, based on the GIS and "cost distance weighing" mapping analysis tool, to construct the landscape eco-security pattern of Eucalyptus introduction by integrating the biological factors and landscape factors into minimum cumulative resistance (MCR) model and combining the "source" extended ecological process with Landscape pattern. This can be a reference approach to constructing the landscape eco-security pattern for the exotic tree introduction in other areas. (2) the components of ecological security pattern such as corridor, radiating routes and strategic point etc. indentified by the minimum cumulative resistances surface which were derived from the GIS-based and MCR model using land cover types, altitude, slope, soil texture and road etc. as resistance factors can preserve ecosystem functions in Eucalyptus-introduced and affect positively the species migration and diffusion in " protection source", which was secondary evergreen broad-leaved forest in natural habitat in this study. By using the minimum cumulative resistance threshold values, we divided the eco-buffer zone, eco-transition zone, eco-fringe zone, farming zone and residential zone for the landscape eco-security construction. We also defined the banned zone and planting zone for Eucalyptus plantation. The medium-security and high-security landscape eco-security patterns were developed on the basis of minimum cost but maximum ecological and economic benefit for the introduction areas in Eucalyptus plantation. To achieve this goal, there will be two schemes. In the first scheme, medium-security and high-security areas for Eucalyptus plantation account for 33.48% and 19.27% of total study areas. In the second scheme, medium-security and high-security areas for Eucalyptus plantation account for 28.37% and 15.17% of total study areas. (3) the second scheme of medium-security pattern could fit ecological and economic conditions of Lancang County better when compared these two schemes from the expansion effect of "source", protection range, management cost, difficulty level, eco-environment capacity as well as economic and social development. In the second scheme, the large and small patches of protection 'sources' were spaced in-between, and large patches can work well for protecting the species and ecosystems better, small patches could be settled foothold to protect distributed rare species or ecological niches. As the "source" patches were small and concentrated, the fragmentation was relatively low, so the protection and management of the "source" will be less difficult and costly. There were 22 corridors and combined circular, so the connectivity among "sources" was good. There were 6 radiating routes, meaning less opportunity for "sources" expansion. There were many strategic points of native tree species for improving the integrity of the "sources". All these results may provide some useful references for developing eco-security strategies in the study areas.