From the deregulation of electricity industry in China, a comprehensive model of regional electrical market structure, ownership structure and power generation enterprises' efficiency was built by using theory of industrial organization. Data from listed company of electricity industry during 1999～2006 were analyzed. The hierarchical linear models were used to examine these relationships. Results show that the decline of market concentration and the proportion of the state-owned are propitious to the enhancement of the corporate efficiency respectively. It is also found that the number of electricity enterprises and the proportion of the state-owned have a negative interaction effect, however, this effect is not significant.