The direct or indirect influences of ecological process caused by roads can extend from population to landscape level. On the large scale, the influences are created and expanded by the road networks. The existence and extension of road networks affect adjacent landscape pattern and process within the road effect zone. The landscape fragmentation also brings pressure on regional ecological security. Considering the particular natural environment and ecological characteristics of Longitudinal Range-Gorge Region in Lancangjiang River valley of Yunnan Province, estimation of road effects on ecosystems in the region will be more reasonal and practical. The paper takes Jinghong county as an example to quantify the landscape pattern affected by road construction and to assess its effect on regional ecosystem. Buffer, comparison and scenario analysis were used to elucidate the effect of road on landscape pattern and its ecological risk. Using GIS software, road buffers were divided into different classes and the buffers can be considered as road effect zone. Seven scenarios were set as no road, rural road networks overlay, third class road overlay, second class road overlay, first class road overlay, expressway under construction overlay, and planning first class road overlay. Land use and landscape pattern index were compared to discern the changes under different scenarios and in different buffers. The results showed that forest and shrub decreased while farmland and constructed land increased in the past 20 years in the studied area. In addition, the land use change rate increased near roads while landscape pattern diversity index, eveness index, patch density, and human-disturbing index decreased. Existence of road networks has been potential driving force to region land use change. The analysis of land use in road effect zone showed that forests were mostly affected by road, followed by grassland, farmland or shrub land. The largest patch number affected is farmland near the low-level roads while it is forest near high-level road. Scenario analysis showed that the fractal dimension index, patch number, and average patch area decreased with development of road networks. Different road networks showed that low-level roads such as rural roads and third class roads contributed most to the regional patch number and area change. In general, expressway plays little role on the landscape pattern change.