Experiments of formaldehyde emission from plywood panels were conducted using the closed environment chamber at various relative humidity and temperature conditions, the influence rule of relative humidity and temperature on formaldehyde emissions of plywood panels was studied. The experiments showed that formaldehyde concentration in chamber increased rapidly during the early 3h, and reached equilibrium at 7~8 h. Concentration of formaldehyde increased between 1.1~1.3 times for a 20% rise in relative humidity. A 5℃ increase in temperature could increase the emission by 1.3~2.5 times. The key parameters of formaldehyde emission, the initial mobile concentration, C_m,0, the material-phase diffusion coefficient, D_m, and the material/air partition coefficient, K, were calculated by using variable loading degrees. The effect of relative humidity and temperature on emission parameters was discussed, and the models about them were developed. The formaldehyde emission parameters of plywood panels at different environment conditions were predicted, and the simulated results matched the experimental data well.