The powder-containing composition of the present invention comprises an aqueous solvent, a cationic polymer present in the aqueous solvent, and a powder having a negative charge on the surface in the aqueous solvent and having a BET specific surface area of 50 m2/g or more. The cationic polymer comprises 15% to 85% of a first component which is an amine-containing (meth) acrylic component, and 15% to 85% of a second component which is a vinyl-based component having a heterocyclic ring or an amide, based on the molecular weight of the cationic polymer. The ratio of the mass in the composition of the cationic polymer to the total surface area in the composition of the powder is 0.1 μg/m2 to 2500 μg/m2.本發明之含有粉末之組成物係含有：水系溶劑、存在於水系溶劑中之陽離子性聚合物、及在水系溶劑中表面帶負電荷且具有50m2/g以上之BET比表面積之粉末。相對於陽離子性聚合物之分子量，陽離子性聚合物係含有：屬於含有胺之(甲基)丙烯酸系成分之第1成分15%至85%、及屬於具有雜環或醯胺之乙烯系成分之第2成分15%至85%。陽離子性聚合物在組成物中之質量相對於粉末在組成物中的總表面積的比為0.1μg/m2至2500μg/m2。
