Research Paper 200, July 2003, viii, 71 pp.  Canada is now overwhelmingly an urban nation. More than 80% of Canadians now live in urban areas and over 60% in the larger metropolitan regions. As those cities change, so too does the nation. In recent decades, Canadian cities and the entire urban system have undergone a transformation. As the factors driving change have evolved, so must our ideas evolve about how the urban system is organized. Drawing on research on urban Canada over the last thirty years, this paper provides an overview of change in the Canadian urban system for the period from 1971 to 2001. Particular attention is paid to the importance of changes in the national environment – in the economy, the demography, and the public sector – and to shifts in the global environment that have in combination reshaped the urban system. In future, growth is likely to become more uneven, with further concentration in a few large metropolitan regions and with much of the rest of the country in relative decline. The direction of evolution of the urban system is likely to become more dependent on forces emanating from outside the country.