CuBTC　(BTC　=　benzene-1,3,5-tricarboxylate),　an　metal-organic　framework　(MOP),　is　active　for　CO　oxidation.　The　activation　temperature　has　a　significant　effect　on　its　activity.　In-situ　diffuse　reflectance　Fourier　transform　infrared　spectroscopy,　powder　X-ray　diffraction,　scanning　electron　microscopy,　and　thermogravimetric　analysis　and　differential　scanning　calorimetry　(TGA/DSC)　characterization　showed　that　the　coordination　of　CO　on　the　open　metal　sites　occurred　during　the　oxidation　reaction,　and　more　open　metal　sites　in　the　CuBTC　framework　gave　a　higher　activity.