Some oxide smoke particles which were prepared by burning metals in a gas mixture of 80% Ar and 20% O2 were studied by electron microscopy. CaO smoke particles grew in single crystal cubes. In2O3, Sb2O3, Bi2O3, Cu2O, SnO2, CuO, and WO3 smoke particles grew in single-crystal octahedra or sometimes grew in spheres or more complicated polyhedra. Particles with layer structure such as SnO and PbO grew in thin plates. It is shown by scanning electron microscopy that smoke particles grew by coalescence in which two or more single particles joined in definite orientations.