Empirical analysis based on 31 countries of OECD further indicates that narrowing fluctuation in business cycle is a universal trend for all countries with continuously developing of economy and perfecting of system and that its internal reason is “market growth”. Defining market growth as “continuously maturing market mechanism and decreasing magnitude of information asymmetry”can well explain high level convergence trend in business cycle in transition countries and narrowing fluctuation trend of business cycle in developed countries. Thus, we need to correctly understand “market growth” and take the magnitude of information asymmetry as an important standard to measure market maturity, meanwhile, we should stick to and accelerate marketization reform, in order to rapidly attain the economic goal of China’s economic high level convergence, improving economic growth quality and so on.