Abstract: Based on the analysis of the mechanism of urbanization on carbon emissions of construction sector, applying the LMDI decomposition method, this paper decomposes the effects of urbanization on carbon emissions of the construction sector into scale effect(including fixed asset investment benefit effect, household income effect, population density effect and space scale effect), structure effect, and technical effect, and further analyzes the impact of these effects on carbon emissions of the construction sector in different urbanization stages and provinces. Results indicate that:(1)from the temporal perspective, in the process of urbanization from the primary stage to the intermediate stage to the advanced stage, both the fixed asset investment benefit effect and the structural effect have been continuously enhanced on carbon emissions of the construction sector, the difference is that the former effect has a positive impact(19.37 million t, 129.41 million t, and 369.48 million t),the latter effect has a negative impact(-4.14 million t, -138.25 million t, and -141.49 million t);while the other effects all have shown the "inverted U" trend, but with different directions. Among the other effects, both household income effect(-1.80 million t, -18.63 million t, and -5.23 million t)and population density effect(-2.99 million t, -53.04 million t, and -15.39 million t)have negative impacts, the space scale effect has a positive impact(16.55 million t, 137.51 million t, and 60.14 million t),the technical effect has a positive impact firstly and then a negative impact(38.05 million t, 325.26 million t, and -90.53 million t).(2)From the spatial perspective, the fixed asset investment benefit effect has a positive impact in the advanced stage, a negative impact in the intermediate and advanced stages, with a prominent contribution rate(the first or the second place);the household income effect negatively influences economically developed provinces, and it positively influences economically underdeveloped provinces with weak contributions; the population density effect, only in Beijing, Tianjin, Shanghai and Hebei, has a positive impact, but its contribution rate is relatively low(mostly ranking the fifth place);the space scale effect has a positive impact in all provinces, especially prominent in provinces and cities of the intermediate stage(top three);the structure effect has made outstanding contributions(ranking the first or the second),and its outcome is opposite to that of the fixed asset investment benefit effect in each province; the technical effect only has a negative effect in Jiangsu and Xinjiang, the contribution rate in different provinces varies greatly. Finally, this paper indicates that the government should firstly consider the stage of urbanization, and then formulate the low-carbon urban development planning and the energy-saving and emission reduction measures in the construction industry.