The effect of catalyst systems Co2B/rare earth oxides on the properties of hydrogen generation of NaBH4 was studied. The results show that doping with Co2B/CeO2 and Co2B/Sm2O3 increases the amount of hydrogen generation of NaBH4 obviously. Among all samples, the sample doped with Co2B/CeO2 with ratio of 1:1 has the largest amount of hydrogen release reaching about 274 mL. However, the investigation on the rate of hydrogen release indicates that doping with Co2B/rare earth oxides decreases the rate of hydrogen release obviously. Furthermore, the analysis on the microstructures of the reaction products of the samples doped with Co2B/rare earth oxides shows that, doping with Co2B/rare earth oxides makes the microstructures of the reaction products looser compared with doping with Co2B. Significantly, the investigation on doping with Co2B/CeO2 shows that the porous structure is helpful for improving the amount of hydrogen generation. However, the investigation on the samples doped with Co2B/La2O3 and Co2B/ Sm2O3 indicates that there is no direct relationship between the amount of hydrogen generation and the porous structure