In order to reveal the influence of gentrification of Chinese cities on urban form and the urban form characteristics of gentrification neighbourhoods, the urban fuzzy index (I_UF) was applied to coordinate the characteristic parameters of space intensity value and space structure value of urban form based on two typical gentrification neighbourhoods in Shanghai. Results showed that the quality of urban form of most gentrification blocks were scored more poorly than conserved blocks or partly gentrified blocks, which was mainly due to high floor area ratio, closure, and space isolation. The gentrification blocks with high I_UF were mainly characterized by good accessibility and mixed-use development. The fuzzy comprehensive assessment method can objectively reflect the urban form characteristics of the research area and supply an effective approach for the quantitative analysis of urban form. The research results will provide guidance for the formulation of urban reconstruction, design, and planning schemes.