Abstract: Ecological risk assessment is a hotspot arising in recent 20 years, being an integrated junction of geography, ecology, and environment risk evaluation. The study of ecological risk is helpful for understanding local ecological environment, reducing ecological risk, and finally improving the interactions between human beings and nature. Taking the Bohai rim, a typical region of sharp contradiction between population and land, as a case, this paper assessed the ecological risk of five provinces (municipalities) around the Bohai Sea by referring to USEPA framework of ecological risk and combining the methodologies of grading and ordering in relative risk method .Different materials and methods were applied in different steps of the assessment framework. For risk receptor analysis, the ecological endpoints were expressed in ecological capital loss, while the environmental vulnerability was calculated by principal component analysis and weighted layer stack methods according to the index system. Then, the structure vulnerability was evaluated by  landscape index approach based on land use data and vegetation patches data. In the study area, the typical regions with high integrated ecological risk were sea-land interaction belts, mountainous and hilly areas, and cities, while those with low ecological risk were mainly distributed in plains and some hills, where the topography was relatively gentle with low relief, water and heat conditions were favourable, vegetation was dense, and natural disasters frequency was relatively low. For the high risk areas, it would be critical for risk prevention.

Key words: Solenopsis invicta,  entomopathogenic fungi, brood care, grooming, social behavior.