Abstract: Orientation ratio is an important characteristic parameter of oriented flakeboard. Taking sound velocity ratio (SVR= V11 / V) as orientaton ratio, this paper studies the relationship between the ratio, V / V, and average alignment angle 0; as well as the strength ratio, MOE / MOE, at the same time inquiring into the validity through calculating modulus of elasticity of oriented flakeboard by sound velocity. The result shows that the formula MOE=p ?V2 amended by a coefficient can calculate modulus of elasticity of flakeboard very well, its error is < 5%.