This paper proposes that optimizing the extent of China’s potential economic growth rate decline constitutes an essential issue in macroeconomic regulation and control against the backdrop of China’s entrance into a gear-shifting phase of its economic growth.This article focuses on three key propositions concing recent macroeconomic regulation and control:make a difference in a stable situation, a reasonable growth range, and intermediate-high growth,and conducts a relevant quantitative study.Finally,the paper puts forward some suggestions regarding macroeconomic regulation and control policy:rather than securing the lower limit,it would be better to seize the middle line. This paper also proposes that in order to maintain current and future intermediate-high economic growth,two gracious spaces brought by two huge disparities should be adequately employed:development space brought first by regional disparities and second by the gap between urban and rural areas.