A fluorescence molecular tomography system for in vivo tumor imaging is developed using a 748-nm continuous wave diode laser as an excitation source. A high sensitivity cooled charge-coupled device (CCD) camera with excitation and emission filters is utilized to obtain the excitation and fluorescence images. The laser beam performs fast raster scanning using a dual-axis galvanometric scanner. The accuracy of the laser spot position at the source window is within +-200 \mum. Based on the phantom experimental results, the spatial resolution is less than 1.7 mm, and the relative quantitation error is about 10%. In vivo imaging of a tumor-bearing nude mouse tagged with near-infrared dye demonstrates the feasibility of the system.