The concept of leaf economics spectrum (LES) has attracted much attention and debate since its emergence. It for the first time provides quantitative analysis of plant functional traits and their relationships on the global scale,hence quantifying and generalizing the context and variations of the trade-off strategies. This is of great theoretical value, and provides a useful research method and scientific ideas for subsequent study on plant traits and their functions. In this paper, we try to comprehensively review the meaning, contents, relevant verifications and objections about LES, and to explore its underlying mechanisms. In addition, we emphasize the multi-scale and multidimensional extensions, integration and potential applications of LES. Currently there are still several shortcomings about LES research in China, and we outlook the development of LES theory domestically and abroad. It may be of significance for ecological researchers to establish and exploit jointly a global database on plant traits.