Longitudinal and transverse modulus of rupture(MOR) tests of plybamboo form with different moisture content were performed. The results show that both longitudinal MOR and transverse MOR decrease with the increasing of the moisture content of the plybamboo form. At low moisture content stage MOR of the plybamboo form decrease linearly with the increasing of the moisture content of the plybamboo form. Curve regression equations of longitudinal and transverse MOR of plybamboo form were constructed by the method of numerical fitting, and linear regression equations at low moisture content stage were also constructed. Decline of plybamboo form strength itself and bonding invalidation lead to the decrease of MOR. The results of variance analysis and significance test of four regression equations show that all the regression equations achieve very significant level.