Hollow multiple-Ag-nanoclustes- C-shell nanocomposites (Ag@C) were prepared by grafting carbon dots (CDs) with silver nanoparticles (AgNPs) using silane coupling agent(KH550). The as-prepared Ag@C nanocomposites show strong bactericidal effect against both gram-positive and gram-negative bacteria. The as prepared Ag@C nanocomposites exhibit low cellular toxicity.