County cities' sustainable development is one of the most important foundations to both the promotion of ecological civilization and the realization of the strategic goal of new urbanization. Researches on urban expansions aimed to the protection of the values of ecological service functions are also of paramount importance to theoretical and practical domain. The birthplace of "Two Mountains Theory" of Anji County in Zhejiang province had been taken as the study area and its adjacent city of Guangde was chosen as a contrast. Two different development scenarios were set based on the SLEUTH model, one was the continuing of the current development mode and the other was largely considered the protection of ecological service functions. Four ecological service functions were further distinguished based on their ecological values which were regulation service, supply service, support service, and entertainment service. Expansion of construction land in the year of 2030 was simulated under the two different scenarios. Then a detailed comparative analysis was conducted to reveal the differential impacts on county economy in Anji County and Guangde City based on spatial statistics. The results show that:(1) under the scenario of continuing the current development mode, both counties were sprawl around the existed construction land. Outwards spreading were dominant and accompanied by small inner fillings. Main and large expansion areas were those that around the county towns and shown a tendency of contiguous. Such patterns might have some negative impacts on ecological environment; (2) under the protection scenarios of ecological service functions, expansion of construction land in both counties were restrained to some extent. The lowest expansion area of Anji County would be decreased at least by 1.43% and by 7.57% in Guangde City; (3) Compared with the current development scenario, the amount of forestland occupied by construction land in both counties were decreased significantly. It was decreased by 1.79km²in Anji County and by 2.44km² in Guangde City respectively; (4) Compared with the city of Guangde, the expansion of construction land in Anji County was more relied on the conversion of farmland. Since Anji County is the first one to take ecological protection road and has already adjusted its development mode, the impacts of construction land expansion on ecosystem services and county economy were smaller than that in Guangde City.