This research aims to find out effective approaches to improve the low carbon economy efficiency of China and to promote its low carbon economy development. This paper utilizes two kinds of data envelopment analysis models to estimate the economic efficiency and low carbon economy efficiency of China. It takes carbon dioxide emissions as an undesirable output and compares them to find out the different performances of economic growth in various regions in China in the context of low carbon economy development, and then explores the potential determinants of low carbon economy efficiency for different regions in different periods. The results show that low carbon economy efficiency is much lower than economy efficiency in most areas in China. Additionally, both low carbon economy efficiency and economy efficiency show a slow downward trend in most provinces in China from 2000 to 2011, which was followed by a slight increase in 2012. Moreover, low carbon economy efficiency and economy efficiency show obvious geographic characters. We propose some policy implications. Several policy implications are also provided for various areas to improve low carbon economy efficiency.