The mixed oligopoly model analysis shows that the higher the diversification degree of ownership is, the higher the mixed market economic output is. By using the panel data of 255 cities above prefecture level of China during 2003-2013, by using diversification index of ownership and the square of the proportion of scaled industrial output of four economic types and by using quantile regression analysis, this paper empirically tests the long-term effect of ownership structure and different ownerships on urban economy and their regional difference, and the results show that mixed ownership economy can indeed effectively promote the urban economic growth, that in the different ownership economy, the driving effect from state-owned economy on economic growth is with universality throughout the whole nation, that the driving effects on economic growth from private economy, Hong Kong, Macao and Taiwan economy and foreign funded economy are of greater regional differences. The development of mixed ownership economy is of great significance to China’s market economy development, but currently the degree of mixed market development has significant regional difference, and China should choose suitable industries to develop mixed ownership economy in appropriate places.