Abstract: Dongying is a developing petroleum resource city, the reason that locates in the Yellow River Delta where sea-land change activity, natural disasters aggravate and ecological environment fragility make it the composite of resource-based city and coastal ecological fragility city. The man-land relationship tension and land use/cover change have unique regional character, so it is practical significance to analysis the land use/cover change and the internal rule of ecological security. Based on RS and GIS techniques, the land use/cover change and the spatial evolvement rules of ecological security in 1996 and 2005 were studied, and the digital simulation of ecological security spatial evolvement pattern was conducted. The results indicate that the cultivated land was the primary type, the proportion of unused land and secondary saline habitat were much bigger, the proportion of residential and mining land increased quickly, and the conflict between the producing-construction of oilfield and eco-environment conservation was keen-edged in the recent ten years. The ecological security risk was worsen, the center of ecological risk had transferred from the district of Guangrao to Dongying, oil field and the correlative industry became the main reason of the ecological risk increasing, at the same time, the tremendous pressure of eco-environment came form the breakage of wetland ecosystem, grassland degradation and land salinization.