Abstract: The coming of knowledge economy era poses a newproblem to the development of diversified economy inpetroleum enterprises. This paper analyzes the petroleumdiversified economy in the following aspects : how toinvestigate the market to determine the position ofproducts in the market, how to analyze the marketenviroment to determine the industrial structure ofdiversified economy, and how to adjust and reformEnterprises of diversified economy. Appropriate measuresthat should be taken are also presented in this paper.