A pot experiment was conducted to study the effects of applying citric acid at different time and times in 10 ways for remediation of Cd-contaminated soil and cadmium accumulation in shoot by C. argentea for providing the reference for screening the best citric acid application method to improve Cd remediation efficiency by C. argentea. Results revealed that the biomass of each section of C. argentea was increased after the experiment, in which citric acid was applied before transplanting, and balanced for two weeks after mixing (CA+Bal) had the largest effects, the biomass of leaves, stems, roots and aboveground increased than CK treatment by 66.18%, 67.22%, 65.58%, and 66.92%, respectively. In the treatment of citric acid applied a single in the fourth week (CA+4) and the treatment of two equal amounts in the fourth and fifth weeks (CA+4/5), Cd contents in the aboveground were significantly increased than CK treatment by 67.18% and 66.82%, respectively; Cd accumulation in the aboveground parts of C. argentea under the treatments of CA+Bal and CA+4/5 were significantly increased than CK treatment by 139.62% and 129.59%, respectively. Therefore, citric acid can be applied prior to transplanting, and balanced two weeks after mixing and two times in equal in the fourth and fifth weeks to increase the remediation efficiency of Cd-contaminated soil by C. argentea.