This study contributes to a better understanding of urban growth through the use of statistics. It has two prime objectives: 1) détermine the relevance of allometric growth coefficients calculated using data at six points in time, and 2) identify and measure the various forces linked to the growth of Quebec's urban System. The distribution of the growth of the 62 principal urban centres is examined. The extremely complex nature of the growth phenomenon was quickly apparent. For this reason fifty-six variables were selected for study. Factor analysis reduced this complex data matrix to thirteen factors. Of these, age of the inhabitants and age of the urban centre, spatial and social position, dynamism of the agglomeration, and urban form were the most important in explaining the growth of Quebec's urban System.