For filling the room in China of the research on wood density including the differenceswithin annual rings,a wood densitometer MWMY was built by the Research Institute of Wood Industry,CAF,and the Beijing Kexin Institute of Mechanical and Electrical Techniques,The mainproblems resolved in the research and manufacture work for the densitometer were reported,in-volving instrument selection,overall design,aperture structure,calibration of measuring system,determination of microdensitometrical characteristics,software design,and accuracy evaluation. The measuring accuracy of the MWMY densitometer proved to be at the the same level as that ofsimilar foreign devices.Several creations were made relative to the aperture,software,calibration,and wood sample making.