Abstract: Grassland easement system is an important private law system for balancing economic，ecological and social benefits of grassland resources. Comparing systems of grassland easement in foreign countries, we find that ‘omission principle’ of easement in Roman law limited the exertion of easement function. It has great practical significance on safeguarding ecological benefits of grassland resources that recognizing ‘act principle’ being presence principle of easement, constructing internal logical structure of grassland easement by ‘affirmative easement’ under the framework of the Real Right Law of People’s Republic of China to impose obligation on tenant, and designing system of grassland easement to meet the purpose of ecological protection.