C16 Guerbet alcohol (2-hexyl-1-decanol) was synthesized from n-octanol by using supported CuO-NiO catalyst with KOH. The effects of catalyst support, CuO-NiO loading (%) and CuO/NiO molar ratio on the synthesis were investigated so that the best CuO-NiO catalyst was chosen (CaCO3 supported, CuO-NiO loading 30 w% and CuO/NiO molar ratio is 1∶2). Besides, the effects of reaction temperature, reaction time and catalyst dosage (mass percentage of catalyst and n-octanol) on the reaction were studied. The results indicate that C16 Guerbet alcohol is able to be produced in the presence of CuO-NiO catalyst and KOH. When C16 Guerbet alcohol was synthesized under reaction temperature 240 ℃for 1 h with 0.1 % best CuO-NiO catalyst and 3.0 % KOH added, the yield and the selectivity reached 83.5 % and 87.3 %, respectively.