The growth of urban tourism has received wide attentions from tourism geography. Over the past four decades, China has been witnessed rapid, continuous and non-limit growths of urban tourism in most cities. The local governments and developers were encouraged by this miracle of past growth expectation or plan to a more optimistic glowing future. However, the urban tourism is an open and high mobility subsystem of city system, and its growth is stable and faces limits from both supply and demand sides for a certain period. When tourist demand exceeds its supply, it will lead to overtourism. Oppositely, when tourism supply exceeds tourist demand, which will result in over tourismification. The growth of urban tourism demand curve is stepped. Only when the long-term influencing factors of urban tourist demand continue to undergo major changes, can the growth of urban tourism break through the original limit and enter a new stage. The limit of urban tourist demand stipulates the urban tourism supply and determines the scale and level of tourist facilities such as scenic spots, hotels, restaurants, and shopping mall which are cater to the need of urban tourists within a certain period. This study defines a phenomenon of over tourismification as the status of tourism supply over tourist demand, which is manifested as three conditions: whole over-supply, partial over-supply and no over-supply but facing negative reaction to tourism growth by enterprises and locals. This study also proposes an analytical framework on limits to growth of urban tourism and uses it to empirically analyze urban tourism of Zhuhai city. It is found that middle- and high-end tourist demand of the study city has been stable and faced limit since less constant change in function, status, features and image of Zhuhai city took place and more intense competition from surrounding cities occurred in the past decade. This indicated that the supply of middle- and high-end hotels and other tourist facilities in Zhuhai reached a saturation point and any new more such tourist facilities will make for over tourismification. The conditions of breaking through limit and the relationship between growth of urban tourism and tourism development were discussed and suggestions on the improvement of tourism statistics in China were also proposed.