By using the quantitative index of 'probability of connectivity', this paper analyzed the effects of road network on the landscape pattern, ecological process, and landscape function in the typical areas of Yunnan Province. Road network accelerated landscape fragmentation, and changed the structure, number, and distribution pattern of ecological process dispersal paths, with the effects increased with increasing dispersal ability. The road network generally reduced the landscape function in maintaining ecological process connectivity by > 10% and the patch function by > 40%, and the effect also increased with increasing dispersal ability.