Abstract: The technology of wood mechanical welding which has been invented and developed for more than ten years has been proved to be a wood-gluing technology with great potential. The mechanical welding has been employed to glue Moso bamboo, which is also a lignin-cellulose biomaterial. The tensile-shear strength of the bamboo welded joints has been mainly studied. Besides that, scanning electron microscopy and FTIR were used to study the welded joints to understand the bonding line. The results showed that the tensile-shear strength of the welded joints increased and then decreased with the increase of the welding pressure. The gluing layers of the welded joints are composed of entangled bamboo fibers enveloped by the melted and flowed intercellular materials mainly lignin. The hemicelluloses in the welded joints was the main constituent which was thermally degradated by the heat generated by the mechanical vibration welding. The content ratio of the lignin was increased a little; but there was no such big difference between the cellulose of the welded joints and the natural bamboo.