According to the provisional results of the 2001 Census of India the population of India has passed the one billion mark with a sharp decline from its decadal growth rate of 21.34 per cent over the last five decades. The urban population constitutes 27.8 per cent of the total,with a decadal growth rate of 31.2 per cent.The level of urbanisation is 2.1 per cent higher than in 1991. The density of population has increased steadily from 117 persons per km2 in 1951 to 324 persons per km2 in 2001.Urban agglomerations or cities with a population of more than one million have increased from 22 in 1991 to 35 in 2001 with Greater Mumbai being the largest at 16.4 million.The Mumbai Metropolitan Region is the largest urban agglomeration in the coun-try. For the first time detailed data on slum areas in the country have been collected in the 2001 census.The total slum population in the country is 40.3 million comprising 22.6 percent of the total urban population of the towns which reported slums.The largest slum population was registered in the State of Maharashtra. Around 6 per cent of Maharashtra’s population lives in the slums of the state capital,Greater Mumbai.