The article discusses the relationship between strategic environmental assessment (SEA) and regional environmental impact assessment (REIA). It explains how SEA improves project environmental impact assessments (EIA) in five key ways and emphasizes the importance of implementing REIA. The study shows that EIA for regional development plans is a crucial part of SEA in countries like China. SEA not only enhances EIAs but also promotes sustainable development. China's environmental regulations have pushed for the implementation of SEA, signaling a move towards more advanced development stages.