Formaldehyde emission levels of four kinds of wood-base d panel (Plywood,Blockboard,Particleboard and MDF) were studied with perforate m ethod and large chamber method.The result indicates that the perforate value of a panel has a direct proportion to the Resin/wood ratio of the product.There was a clear consistency in the test results between perforate method and large cham ber method.Blockboard gave the highest formaldehyde emission level in large cham ber test.Formaldehyde emission rate of the wood-based panel decreases in accord ance with exponential decay in large chamber test condition.A formula to predict the formaldehyde emission level of the wood-based products was tentatively put forward in this paper.