Flower-like Co–La oxide micro/nanomaterials have been synthesized via an ethylene-glycol-mediated process, under the condition of that the mole ratio of lanthanum nitrate (La (NO3)3·6H2O) and cobalt nitrate (Co (NO3)2·6H2O) was 1:1 (based on the amount of Co (NO3)2·6H2O 0.002 mol), the dosage of urea was 2.2 g, the dosage of tetra-butyl ammonium bromide (TBAB) was 6.0 g, with magnetic stirring heating under 170 °C for 60 minutes in the 150mL ethylene glycol, the prepared precursors of Co–La oxides have regular flower-like morphology, in addition, the amount of TBAB and urea plays a significant role on the synthesis of the precursors. The flower-like Co–La oxides micro/nanomaterials were prepared after the precursors were calcinated in the muffle furnace at 800 °C for 2 h, the morphology, crystal properties and element distribution of the products were investigated by the analysis of SEM-EDX, XRD and BET, etc. The structures of these products with regular flower-like morphology are on the micrometer scale, which are hierarchically composed of nanosized building blocks, with highly polycrystalline nature, and the Brunauer–Emmett–Teller (BET) surface area of 68.5 m2/g. Therefore, those micro/nanomaterials have been developed as promising catalytic materials for their not only keeping the high surface area of nanomaterials, but effectively inhibiting aggregation.