Abstract: "People-oriented" is the core component in the process of high-quality development.The "bottom-up" demand-side multidimensional goal provides a new perspective for understanding the connotation of urban vitality.An evaluation system of urban vitality from five dimensions of economy, society, space, culture and ecology was constructed in this study.The entropy-TOPSIS model, Theil index, spatial autocorrelation analysis and obstacle degree model were used to explore the evolution law of urban vitality in the Yangtze River Delta (YRD) region from 1996 to 2021.The results showed that: (1) The urban vitality in the YRD was rising steadily.The vitality of cities in the YRD showed a steady upward trend.The economic vitality was found to play a dominant role in the vitality system.(2) The spatial differentiation and agglomeration characteristics of urban vitality were obvious.The vitality of the core city was obviously higher than that of other cities, forming a "Z-shaped" spatial agglomeration area, and the regional urban vitality showed a "core-edge" structure.(3) The classification of urban vitality patterns showed obvious inter-provincial spatial differences.The vitality of Jiangsu province decreased from south to north.Anhui province faced the dilemma of low vitality level, while Zhejiang Province showed high development potential and stability.(4) Spatial, economic and cultural dimensions were identified as the key dimensions affecting urban vitality.The number of mobile Internet users, the number of patent authorization applications and the proportion of tertiary industry in GDP had significant effects on urban vitality.Future urban development strategies should consider multi-dimensional development, strengthen support for core cities, and promote resource flow to promote coordinated development and comprehensive enhancement of vitality within the YRD region.