Porous vaterite particles exhibit good biocompatibility, degradability, and favorable physical and chemical properties, making them promising candidates for drug carriers. However, challenges such as low loading capacity, burst release effect and limited antibacterial properties hinder their practical applications. Herein, submicron vaterite particles were synthesized at low temperature and modified by stearic acid, and the resulting modified vaterite particles (Vc) possess exceptional loading capacity towards a typical anticancer drug - doxorubicin. Quaternary ammonium chitosan (QCS) with antibacterial properties was synthesized by chemically modifying chitosan and was coated onto the surface of Vc/Dox through electrostatic adsorption. Ag