Abstract: Based on the principle of heterogeneous nucleation and micro-mixing in the impinging- streamrotating packed bed (IS–RPB) reactor, the liquid phase cladding and interfacial reaction was adopted to prepareγ–Al2O3/TiO2 nanopowder by using nanometric TiO2•nH2O particles as base material and AlCl3•6H2O solution as cladding phase. The dispersion and the liquid–solid mixing of nanoparticles in the high gravity field in the IS–RPB reactor were also discussed. According to the spectra of FTIR, TEM Zeta and XRD, it was inferred that the Ti–O–Al bond was formed at the interface of the coating layer and the surface of nanosized TiO2 particles. The thickness of Al2O3 membrane with sponge structure was about 5nm.