Ti(C,N)nanoparticles were added to an Al-0.3Ce alloy by ultrasonic treatment.Further annealing at 570℃ for 4 h afforded the ultimate tensile strength of 79 Mpa and elec-trical conductivity of 64.0% IACS for the Al-0.3Ce alloy with 1.5 vol%Ti(C,N)addition.Both performance parameters were improved by 23.4% and 0.6% IACS,respectively,compared with those of casting refining pure aluminum(64 Mpa and 63.4% IACS).This could be explained by the following rea-sons.The addition of Ti(C,N)nanoparticles could significantly refine the grain of Al-0.3Ce alloy.Notably,most of the coarse strip-shaped second phases distributed at the grain boundaries in Al-0.3Ce were also transformed into spherical microparti-cles distributed in the grains,with micro-nano hierarchical structures comprising orientated nanosized strip phases with lengths of~400 nm and widths of~100 nm.Moreover,a fine micro-nano hierarchical spherical structure could be obtained after annealing at 570℃ for 4 h.The numbers of micro-nano hierarchical spherical structures also increased due to the precipitation of pseudosolution Ce from the aluminum matrix during the annealing treatment.