Sustainable urban materials management is significant for environmental sustainability. This study identifies key economic sectors for sustainable urban materials management using urban physical input-output (PIOT) table and hierarchical cluster analysis method to mitigate urban air pollutants (comprising CO2, SO2 and NOx) and examines uncertainties. Suzhou city in China is taken as an example. Key economic sectors in Suzhou considering direct amount are production and supply of electric and heat power, smelting and pressing of ferrous metals, services, other manufacturing, textile, nonmetallic mineral products and chemistry, while key economic sectors considering accumulative amount are agriculture, construction, production and supply of electric and heat power, services and smelting and pressing of ferrous metals. Uncertainties for sustainable urban materials management are consistent with the development stage of the economy. Thus, when constructing urban PIOT for a particular city based on monetary input-output table (MIOT) of another city or province, the development stage of the city or province whose MIOT is used should be similar to that of the particular city. If not, lower and upper limits for the development stage should be set to investigate uncertainties. (C) 2012 Elsevier Ltd. All rights reserved.