Based on the constructing practice of the China-Seismology-Journal-Paper (CSJP) documental database (English edition) for several years, this paper deals with the significance and complexity of the quality control in the construction of the CSJP documental database (English edition) under the decentralized condition. It presents the construction mode of the documental database, and the quality control mode, control objective and control measures in the process of decentralized indexing for documental data. It is pointed out emphatically that in order to guarantee the quality of the CSJP decumental database (English edition), the indexing staffs must adopt firmly the idea of quality first, and it is necessary to establish a control centre with high-degree authoritativeness and high efficiency administration.