The catalytic performances of several bis(acetylacetonato)metal complexes [Cu(acac) 2 , Zn(acac) 2 , TiO(acac) 2 , VO (acac) 2 , MoO 2 (acac) 2 , and WO 2 (acac) 2 ] were investigated for the crosslinking reaction via transesterifications in the ethylene-vinyl acetate copolymer/tetraethoxysilane (EVA/TEOS) composite system by means of dynamic attenuated total reflectance Fourier transform infrared, solvent swelling, and solid-state 29 Si cross polarization/magic angle spinning nuclear magnetic resonance techniques. Results of the kinetic examination revealed that MoO 2 (acac) 2 and WO 2 (acac) 2 exhibited a higher catalytic activity than di-n-butyltin(IV) oxide, which is a catalyst most commonly used for the transesterification process in polymer system, but has a toxic effect on the environmental health. And furthermore, the crosslink density and final siloxane network structure of crosslinked EVA/TEOS composites are found to be greatly correlated with the catalyst used. On the basis of the S N 2-Si pathway, a plausible catalytic mechanism of MoO 2 (acac) 2 and WO 2 (acac) 2 was proposed for the crosslinking reaction via transesterifications of the vinyl acetate moieties in EVA backbone with the ethoxysilane groups in one TEOS molecule. The findings in this study may fill the blank in the high performance and environmentally friendly catalyst in the field of the crosslinking reactions in polymer system and provide useful clue for other transesterifications.