A series of hydroxyl terminated polydimethylsiloxane (PDMS-OH) grafted MF resins (MF-PDMS) were synthesized via an effective method that employing dimethylacetamide (DMAc) as the solvent. The structure and surface chemical composition of MF-PDMS materials were characterized by FT-IR, solid state 1H NMR, XPS and SEM-EDS. The hydrophobicity and thermal properties of MF-PDMS materials were studied by contact angle, immersion and thermogravimetric (TG) analysis. The results indicated that the PDMS-OH has been directly grafted and copolymerized with melamine and formaldehyde in DMAc solvent, MF-PDMS resins have been successfully synthesized. PDMS-OH provided excellent hydrophobicity and thermal stability with MF-PDMS material, when the amount of PDMS-OH was 1.0% (based on the mole of melamine), the water contact angle of MF-PDMS-01 material increased to 91.81°, the surface free energy decreased to 28.1 mN/m, the water adsorption decreased to 2.83%, the residue at 400 ℃ and 700 ℃was 58.03% and 16.60%, respectively.