Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature-programmed desportion/reduction (TPD/TPR) experiments. Pr_2O_3 possesses the similar oxygen storage properties to CeO_2, and its dynamic oxygen storage capacity is 14.9 μmol·g~(-1). The studies on TPD of O_2, H_2O and CO and TPR show that Pr_2O_3 provides more active surface oxygen species and at a lower temperature than CeO_2. It is suggested that Pr_2O_3 can be a well candidate as an oxygen storage component in automobile three-way catalyst. Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature-programmed desportion / reduction (TPD / TPR) experiments. Pr 2 O 3 possesses the similar oxygen storage properties to CeO 2, and its dynamic oxygen storage capacity is 14.9 μmol · g ~ -1). The studies on TPD of O_2, H_2O and CO and TPR show that Pr_2O_3 provides more active surface oxygen species and at a lower temperature than CeO_2. It is suggested that Pr_2O_3 can be a well candidate as an oxygen storage component in automobile three-way catalyst.