A seed-mediated electrochemical method was used to grow Ag nanoplates with controllable size. The sodium citrate tribasic dihydrate was used as the capping agent to control the growth of Ag seeds, and L-ascorbic acid was employed as the reducing agent in electrolyzing growth of Ag nanoplates. Ag nanoplates with size ranging from 250 nm to 2.2 mu m and thickness in several tens of nanometer have been realized. The influence of input electric current, seeds content and reaction time on the size and size uniform of Ag nanoplates were discussed and analyzed. Our method can primly control the kinetic growth process of Ag nanoplates and slow down the reaction rate, and can be easily scaled for mass production. (C) 2017 The Electrochemical Society. All rights reserved.