This paper is based on the controversies which the existing empirical researches on the impact of the basic
factors affecting energy efficiency, have in index selection and direction, using the method of meta-regression to analyze
the related domestic empirical studies comprehensively. We conducted a study on the differences of research design, data
characteristics, time span and the index selection, to check whether these differences cause the controversies in index
selection and direction. The result shows that the research design, empirical methods, and the characteristics of the
selection of indicators have significant impact on the result of empirical researches.