Abstract: Based on the regional study of composition and structure of suburban environment and characteristics of suburban eco environment, with the theory of edge effect as its starting point,profound analysis was made of problems in construction of eco environment in regions interlacing city and countryside. It was held that construction of suburban ecology should be oriented towards: (1)a site for regeneration of urban wastes;(2)a place for consumption,like ecological tourism and agricultural culture;and (3)a pioneer region of modern sustainable agriculture. The aggregating and enlarging effect of the city countryside interlacing regions(marginal interface)on environmental stress in the urban and rural compound ecosystem was analyzed. It has been pointed out that the regulating of suburban agro ecological environment is an essential measure of preventing the conflict between city and the countryside from aggravating.