Abstract: The heat-resistant property, adhesive strength and storage life were studied for Tetramaleimide (TMI) modificated polyphenylmenthylsiloxane phenolic resin (PFSi) by IR, DSC and TG analysis methods. At the curing temperature of tetramaleimide modificated polyphenylmenthylsiloxane phenolic resin(TMI/PFSi), the C C group of TMI was condensed with —CH₂OH of PFSi into crosslinking structure, since the heat-resistant property and adhesive strength of PFSi are increased, the toughness is kept, and the storage life is decreased. At room temperature, a small amount of the COOH, and NH₂ groups of TMI (because of the steric effection, carboxyl and amino of TMI are not all condensed into imide) are condensed with —CH₂OH of PFSi into a small amount of crosslinking structural oligomer, which makes the storage life of TMI/PFSi decrease.