Abstract:The concept of contributivity was put forward in this paper.It can be used to measure the contribution ratio of solid wood properties to LVL strength.The contributivity of 3 poplar clones from plantation was studied and the results shows that poplar with good solid wood properties or LVL with thick veneers gives high contributivity.The average contributivity of good poplar 69,poplar 72 and poor poplar 63 is 74.34%,67.48%and 64.72%,respectively.When LVL is assembled with the veneers of 3.565mm, 2.614mm and 1.545mm in thickness,the average contributivity is 74.00%,67.48%and 58.06%,respectively. In addition,the contributivity of shear strength,modulus of elasticity and toughness is approximated to 80%,which is higher than that of the other 3 properties.