Abstract：Due to lag of settlement monitoring，measured vault crown settlement is merely a portion of total settlement in construction of city metro tunnel，and ratio of measured settlement to total settlement varies notably with ground condition. Therefore，the vault crown subsiding process and its total settlement are important factors for tunnel supporting design and environment controlling. Regression analysis is carried out on vault crown settlement in some section tunnels of First Stage of Shenzhen Metro，which shows that vault crown settlement process keeps to an exponential function，so the unmeasured vault crown settlement can be predicted. The reliability of regression analysis is validated through numerical simulation；and the larger pre-settlement of vault crown is achieved ahead of heading face. Then，the relation between vault crown settlement and ground settlement is analyzed considering the release of stratum stress during tunnel excavation and stratum water-loss effect caused by the flowing out of underground water；and in this way，the complicated relation of settlements in tunneling of First Stage of Shenzhen Metro may be explained. The complicated relation of settlements is related to the lag of monitoring and water and sand in stratum. The conclusion is significant for the excavation，supporting and environment controlling of city metro tunnels.
