Today,the entire society has paid more and more attention to quality of vegetables.The prevention and control of heavy metal pollution on vegetables is an urgent environmental problem.This paper studied on migration and transformation of Si and Cr in soil-vegetables system by making a simulated pot experiment,which is designed to apply Si to artificial Cr polluted soil.It supplied the basis for further study on application of Si to control heavy metal pollution on vegetables.The results indicate:(1) Under various levels of Cr stress,Si cumulate in Brassica chinensis changed and Si uptake by Brassica chinensis's roots is different.A certain level of Si can improve Si content in aboveground part of Brassica chinensis under each level of Cr stress.(2)Cr cumulate in Brassica chinensis decreased as increasing the application of Si at each level of Cr treatment,which shows that Si can decrease Cr uptake effectively.(3)Si inhibited the Cr which is absorbed by roots transporting to aerial part,therefore the contamination of adible part reduced.Cr in roots is hard to be transported to stem under high level Cr stress,but once arrived at stem,it's easy for they to be transfered to leaf.(4)Si reduced each part of Brassica chinensis's accumulation ability to Cr,thus decreased the Cr pollution on Brassica chinensis.