Polyurethane polyurea particles are obtained by an interfacial polymerization reaction between a hydrophobic phase which is capable of forming a three-dimensional crosslinked structure by reaction and is a mixture comprising a polyisocyanate compound and a polyhydroxy compound with the isocyanate groups being stoichiometrically excessive, and a polyamine in an amount not more than one equivalent of the stoichiometrically excessive isocyanate groups in the hydrophobic phase, and by polyurethanization reaction inside the particles.