This study examines China's high-quality economic development by analyzing regional variations and spatial evolution. It constructs a comprehensive index system to evaluate economic development quality across six dimensions: innovation dynamic, coordinated development, market governance, green transformation, open economy, and people's welfare. Using a vertical and horizontal scatter degree approach, the study dynamically measures the High-Quality Economic Development Index (HQEDI) and reveals its spatial interaction patterns through a modified dynamic Spatial Durbin Model. Findings show that China's HQEDI has shown a persistent upward trend and expanding cycle, with significant spatial agglomeration effects. The spatial correlation structure indicates an imbalanced distribution of HQEDI, with Shanghai and Beijing as the central areas, the eastern coast as the secondary center, and the central and western regions in subordinate positions. Under various spatial weights, China's HQEDI exhibits conditional β convergence and positive spillover effects. Convergence rates decrease in the order of "Central-West-Northeast-East," with corresponding convergence cycles increasing in this order. China's economic growth over the past 40 years has been rapid, but has also led to structural imbalances, resource depletion, environmental pollution, and social welfare issues. These challenges have hindered sustainable economic growth and are common to many developing countries. The concept of "inclusive growth" is being adopted globally to explore coordinated and sustainable economic development. China has shifted its economic development model from high-speed growth to high-quality development, emphasizing innovation, fewer structural imbalances, minimal negative externalities, and fairer benefit distribution. Recognizing regional differences in high-quality development is crucial for understanding China's economic development strategy and providing insights for developing countries. Existing research on China's high-quality economic development is limited by arbitrary indicator selection, subjective weight determination, and lack of exploration into regional correlations. Regional economic development imbalance has long been a focus in China's academic community, but most studies have focused on interregional differentiation.This study examines China's high-quality economic development by analyzing regional variations and spatial evolution. It constructs a comprehensive index system to evaluate economic development quality across six dimensions: innovation dynamic, coordinated development, market governance, green transformation, open economy, and people's welfare. Using a vertical and horizontal scatter degree approach, the study dynamically measures the High-Quality Economic Development Index (HQEDI) and reveals its spatial interaction patterns through a modified dynamic Spatial Durbin Model. Findings show that China's HQEDI has shown a persistent upward trend and expanding cycle, with significant spatial agglomeration effects. The spatial correlation structure indicates an imbalanced distribution of HQEDI, with Shanghai and Beijing as the central areas, the eastern coast as the secondary center, and the central and western regions in subordinate positions. Under various spatial weights, China's HQEDI exhibits conditional β convergence and positive spillover effects. Convergence rates decrease in the order of "Central-West-Northeast-East," with corresponding convergence cycles increasing in this order. China's economic growth over the past 40 years has been rapid, but has also led to structural imbalances, resource depletion, environmental pollution, and social welfare issues. These challenges have hindered sustainable economic growth and are common to many developing countries. The concept of "inclusive growth" is being adopted globally to explore coordinated and sustainable economic development. China has shifted its economic development model from high-speed growth to high-quality development, emphasizing innovation, fewer structural imbalances, minimal negative externalities, and fairer benefit distribution. Recognizing regional differences in high-quality development is crucial for understanding China's economic development strategy and providing insights for developing countries. Existing research on China's high-quality economic development is limited by arbitrary indicator selection, subjective weight determination, and lack of exploration into regional correlations. Regional economic development imbalance has long been a focus in China's academic community, but most studies have focused on interregional differentiation.