Abstract: In order to refine basic zinc carbonate,Mg-doped method was selected to reduce grain size of basic zinc carbonate.Detailed process of the method was as follows:a certain amount of magnesium sulfate heptahydrate (MgSO<SUB>4</SUB>·7H<SUB>2</SUB>O) was mixed into zinc sulfate (ZnSO<SUB>4</SUB>) solution,ammonium bicarbonate (NH<SUB>4</SUB>HCO<SUB>3</SUB>) was used as precipitating agent,and then a system of basic zinc carbonate powder whose grain size had been refined was prepared by direct precipitation method.Main factors affecting the grain size of basic zinc carbonate were investigated,and orthogonal experiment was carried out to find the optimum conditions.After research,following conclusion was obtained:doping a certain mass fraction of magnesium to basic zinc carbonate could reduce the grain size of basic zinc carbonate.Optimum parameters:ZnSO<SUB>4</SUB> was 2.5 mol/L,NH<SUB>4</SUB>HCO<SUB>3</SUB> was 3 mol/L,stirring speed was 450 r/min),m(Mg)∶m(Zn)=1.07∶22,reacting temperature was 60 ℃,NH<SUB>4</SUB>HCO<SUB>3</SUB> dropping speed was 12.5 mL/min.Under these process conditions,a system of basic zinc carbonate whose grain size was 9.5 nm was prepared. 