Effects of conditioning equalization treatments on bending strength of wood-based panels were investigated by testing bending properties of medium density fiberboard（MDF） samples and particleboard（PB） samples under varied equalization conditions.Results showed that the bending strength of the samples decreased with increased temperatures and relative humidity（RH）.Either high temperature or high RH had significant effects on the bending properties.Both of low temperature and low RH had different effects on modulus of rupture（MOR） and modulus of elasticity（MOE） of the samples with various thicknesses by one way analysis of variance and t-test analysis.