OBJECTIVE：To ensure the stability of electronic data capture（EDC）system in drug clinical trials and to improve the quality of drug clinical trials. METHODS：The quality control system for EDC system was established and introduced from the formulation of quality control process，establishment of data standard，trial project management，daily management，trial project design，system operation，system function，etc. RESULTS & CONCLUSIONS：Data standard have been achieved through establishing EDC quality control system by our hospital based on attributable，legible，contemporaneous，original and accurate principle. The management of trial project and daily management are conducted through data registration，staff training，the formulation of data management plan，fault emergency treatment，database backup；multiple verification of support data，data lock and export，trial report autogeneration and other functions have been realized by formulating related standard operation instruction，program file，operation manual and quality record. Those aspects improve facticity，accuracy and integrality of data in clinical trials，and lay a foundation for further data mining.