It is crucial for corporations to select a proper development mode in competitive market. Diversification has been one of the most popular development modes that corporations all over the world pursued since 1960's. The relationship between diversification and economic performance is also an important subject for the research in strategic management. This paper re-examines the economic performance of China listed corporations and designs the measure index system of diversification strategy and economic performance. Moreover, it adopts empirical study on the relationship between them through the approaches such as regression model, variance analysis. It attempts to seek for the diversification development mode fit for China corporations so as to enhance economic performance.