Abstract: Landscape pattern optimization is an important safeguard measure to realize sound development of ecosystem health and ecological security. Using granularity inverse method with minimal cumulative resistance model from an angle of enhancing the overall connectivity of ecosystem, a study was carried out to optimize the landscape pattern in Dongfang City, Hainan Pro-vince. Then, specific optimization measures were put forward, so as to provide scientific reference for the construction of the ecological environment in the area. The results showed that 1800 m granularity landscape component is regarded as the optimal structure for Dongfang City. There are 12 ecological sources aggregately, and 32 new ecological landscape patches are needed to increase. Besides, the distribution trend of ecological sources is characterized by a large quantity but small scale in the northwest and small quantity but large scale in the southeast, which is mainly influenced by human disturbance. Ecological resistance surface is constructed by considering the landscape type, ecological resistance and slope gradient synthetically to better express the actual situation of ecological resistance. However, there are obvious differences between dominant ecological resistance and recessive ecological resistance, reflecting the weak ecological area to a certain extent. The district has 23 ecological corridors and 30 ecological nodes. According to the landscape base and functions, this paper classified the corridors and nodes and put forward the corresponding construction mea〖HJ*6〗sures. This study carries out risk assessment of ecological corridors and hot spot analysis of ecological nods in an ecological security perspective for the first time, which determines the key and order of ecological construction. Landscape pattern optimization will enhance the overall connectivity of ecosystem in Dongfang City remarkably, and the optimization results could provide scientific basis for ecological environment construction.

Key words: null hypothesis, significance testing, decisivity., alternative hypothesis