This study was carried out to examine not only the effect and the process of activation of aluminum sulfate for the manufacture of PB and MDF, but also application of the activation treatment to PB and MOF made with MDI adhesive. The results were as follows: 1. For the manufacture of PB, activating effect did not take place Because the low moisture content of 30% in the process of activation treatment made probably insufficient activation. It needs to examine higher moisture content for the uniform and enough activation same as that of MOF. 2. In the case of MOF, Activating effect was excellent, it showed not only better results of MOR 48%, MOE 29%, IB 60% than those of the control but also better dimensional stability. 3. Application of alum activation to the PB and MDF made with MDI adhesive yielded no effects. Maybe it was the reson that the curing mechanism of MDI is different. 4. Modifing the wood surface was the oxidation and wettability was not the variable limiting glueline performance. It is necessary to make a more study about activating reaction.