To tackle climate change,China has to curtail CO_2 emissions from high-emission industries.An outlook of Chinese cement industrys CO_2 emission intensity would facilitate achieving national CO_2 emission reduction targets.The cement industry is one of the basic industries of a country.Cement is the primary component of concrete and extensively used in construction activities.From 1981 to 2015,China became the biggest cement producer in the world since the cement consumption in China has increased from 82.08 to 2348 million tons.As Chinas future urbanization requires cement,the Chinese cement industry is confronting an ambitious reduction target.Here we employed the conservation supply curve and the technology penetration curve to estimate the cost and penetration trend of each energy conservation and carbon reduction technology,based on which we developed three scenarios to simulate future trends in CO_2 emission intensity of the Chinese cement industry.The results indicate that,up to 2050,the CO_2 emission intensity of the Chinese cement industry under basic,cost-effective,and technological scenarios will be 491,431,and 342kg CO_2/ton cement,respectively.Compared to the target set in IEA,only the technological scenario would ensure this target,with a gap of 11 kg CO_2/ton cement under the cost-effective scenario.From scenario analysis we conclude that the Chinese cement industry and related administrative departments should take action(such as,administrative regulation,energy tax,carbon tax)to further promote energy conservation and carbon reduction technologies and mitigate CO_2 emission intensity of different processes.We also suggest several specific energy conservation and carbon reduction technologies to significantly contribute to CO_2 emission reduction.