In the field of catalyst support and adsorption, mesoporous petal-like MgAl2O4 has attracted much attention because of their large surface area, abundant and accessible catalytic sites and not easy to aggregate. Mesoporous petal-like MgAl2O4 was prepared by a molten salt assisted non-hydrolytic sol-gel method with aluminum wire as aluminum source, magnesium powder as magnesium source, absolute ethyl alcohol as a solvent and Na2MoO4 as a molten salt, respectively. The effects of heat treatment temperature and soaking time on the phase composition and morphology of petal-like MgAl2O4 were investigated by X-ray diffraction and field emission scanning electron microscopy. The microstructure of the petal-like MgAl2O4 was determined by transmission electron microscopy (TEM), and the specific surface area and pore volume were measured by N2 adsorption-desorption analysis. The results show that heat treatment temperature and soaking time both have an influence on the morphology. MgAl2O4 prepared has a petal-like morphology with a length of 140-160 nm when the heat treatment temperature and time are 900 ℃ and 8 h. The specific surface area of the prepared MgAl2O4 is 76 m2/g. Based on the results by TEM and N2 adsorption-desorption analysis, the petal-like MgAl2O4 exhibits a mesoporous structure. This work paves a promising approach to prepare mesoporous petal-like MgAl2O4.