The abroad research on the theory of low- carbon city development is including four points contents as follows：the integrated constitute of carbon emission，the density and space of oriented low-carbon city as well as its social construction，the energy consume in life and consumption structure. Whereas, the research content at home on city development theory of low- carbon are including its definition，planning, mode and path，as well as policy support, and evaluating standard system. From the above, the research on low-carbon city development should go deeper and be improved from its research object，research methods，research scale and other aspects because the existing theory are still in exploration stage and not very systematic.