Nanoparticles of TiAl alloy were prepared by the flow-levitation method and characterized by transmission electron microscopy(TEM), X-ray diffraction(XRD) and energy dispersive spectrometer(EDS). The influence of the temperature of the droplets on the microstructure of nanoparticles was studied. Results show that the spherical nanopartilces of TiAl alloy are mainly composed of Ti₃Al phase, with the average diameter less than 100 nm and the original atom ratio of Ti/Al. The particle size and phase constituent are affected by the temperature of droplet.