Road construction exerts great destructive effect on island development, since road network leads to incomplete biological environment and sudden extinction of local species. This paper analyzes main negative ecological effect of roads on the islands. According to relation between species quantity and area in biogeography theory-S=CAZ, this paper combines case study, and researches the evaluation theory and method of island road construction, which is of practical guidance significance to protect and restore island ecosystem and make rational utilization of island resources.
