Aim Multidmg resistance (MDR) remains the major reason for the treatment failure in gastric cancer (GC).microRNAs (miRNAs) were recently found to play critical roles in cancer, but their association with MDR in GC remained not fully understood.Therefore, the screening and identification of key MDR-associated miRNAs would provide potential therapeutic targets for reversing MDR in GC.This study is aimed to reveal the key miRNAs in MDR of GC through functional screening.In addition, we will also try to clarify the function of the miRNAs and their regulatory mechanisms in MDR in GC.Methods In the functional screening, mimics of individual miRNAs were transfected into cells and the drug sensitivity was automatically calculated and recorded in a computer.The in vitro drugsensitivities were judged by MTT assays.