Abstract: The vertical bearing capacity of the flangeweb joint of wood Ijoist (IJ）with different groove depths was tested. The results showed that there were two types of failure to the joint, i.e., the prefailure and the final failure. The prefailure included either shear failure of the glue line between the flange and web or tensile failure perpendicular to the grain of the flange wood at the groove bottom, whereas the final failure was a complete failure including not only the shearing and tensile failure but also the compression failure perpendicular to the grain of the flange wood; and the bearing capacity against the final failure was stronger than that of the prefailure. The results also indicated that the groove depth of the trapezoidal flangeweb joint should be designed to avoid prefailure, the failure appearances reflected the mechanical properties of the flange and the glue line and the vertical bearing capacity of the joint. As a conclusion, this paper pointed out that the vertical bearing capacity of the IJ made of the 90 E LVL as a flange and web grade 3 OSB as a web, whose mechanical properties were complied with the 90E LVL of Chinese Standard GB/T 20241—2006 and the OSB/3 of Chinese Forestry Standard LY/T 1580—2000 respectively, could meet the requirement by USA Standard PRI 400, with the groove depth 9-15 mm even though 12 mm was the best.