The low-carbon economy, which is a global consensus, is the global development trend. Currently, however, the theoretical circle has not clearly expounded the basic issues of low carbon economy such as basic concepts, theoretical connotation and so on. On the basis of reviewing related literatures, this paper studies the theoretical connotation of low carbon economy, holds that low carbon economy is a new style sustainable development model of low energy consumption, low material consumption, low emission and low pollution under energy crisis and climate crisis, is the developmental model to construct low carbon industry and low carbon areas and is to develop low carbon enterprises, low carbon industries, low carbon zones and low carbon cities in order to realize decoupling development of economic growth and carbon emissions, finally, raising scientific category of welfare level of the people.