In recent years，cities all over the world have realized that architecture is a dynamic participant in climate activities. Through ARUP’s analysis of the cost and benefit of efficiency upgrades in large commercial office buildings and multifamily residential buildings in Los Angeles，the report compared the electrification options and energy-saving measures of typical buildings built in different vintage to explain the feasibility of the zero-carbon building target，and pointed out the more profitable energy conservation and emission reduction plan. Finally，under the background of China’s “Carbon Peak，Carbon Neutrality” goal，the recommendations about the climate action of urban buildings were put forward based on the study of decarbonization action in the Green New Deal of Los Angeles.