The conversion of CO 2 into other C1 raw materials is considered to be the best way to solve the greenhouse effect and energy crisis. Reverse water gas shift (RWGS) reaction is the best way to obtain high value-added product raw material syngas and its reactor can be realized in any heavy carbon industry. Here, a series of Ga 2 O 3 À CeO 2 composite oxide catalysts with different ratios of Ga 2 O 3 and CeO 2 were developed by gel sol-gel method. Compared with pure Ga 2 O 3 , CeO 2 , the composite oxides catalysts have smaller grains and exhibit excellent selectivity of CO in RWGS reaction. It was found that Ga 2 O 3 has different reaction intermediates compared with CeO 2 and Ga 2 O 3 À CeO 2 , so it is easy to produce methane under high H 2 conditions, while CeO 2 is beneficial to improve the selectivity of CO. Therefore, Ga 2 O 3 À CeO 2 has the potential to serve as a new and highly selective catalyst for reverse water gas shift reaction.