Characteristics of oxide particles produced by Ti/M (M=Mg and Zr) complex deoxidation have been studied in an Fe–10mass%Ni alloy as a function of holding time at 1600°C, followed by quenching. The size distributions for the particles having different compositions are compared with the particle size distribution in single deoxidation with Ti, Mg or Zr. In most experiments the composition of particles precipitated during rapid quenching was found to be non-equilibrium phase. The formation mechanism of primary and secondary deoxidation particles and the difference in the compositions of non-clustered and clustered particles are discussed. The effects of Ti addition, method of deoxidation and holding time at 1600°C on particle size distributions in Ti/M complex deoxidation experiments are studied.