Catalytic oxidization of formaldehyde appears to be a promising technology for indoor air pollutant control. However, most of the previous studies were conducted under high temperature (>80 °C) and high concentration conditions. The objectives of this study are to determine the efficiency of catalytic technology under room temperature. Decomposition of formaldehyde by three selected catalysts, including one supported noble metal and two transition metal oxides, was studied under room temperature (23∼25 °C) with different concentration, relative humidity and air velocity levels. A singlepass breakthrough test method was used. The experimental results showed that the noble metal catalyst had longer-lasting activity and higher efficiency than the metal oxide catalyst. Further study on the noble metal catalyst showed that its formaldehyde removal efficiency did not change significantly with concentration, but decreased with the increase of relative humidity. The tests with different velocity indicated the important role of mass transfer in the catalytic oxidization process.