Fe3O4@SiO2 nanoparticles were prepared by hydrolysis of TEOS in the presence of Fe3O4 nanoparticles that were synthesized through co-precipitation procedure. Then, thiamine hydrochloride (VB1) was covalently connected with silica to provide a biodegradable, nontoxic and inexpensive NHC ligand for the formation of complex with palladium. This magnetic bionanocatalyst was characterized using FT-IR, XPS, FE-SEM, TEM, EDX, XRD, VSM, TGA and ICP-AES analysis. The Fe3O4@SiO2@VB1-Pd was found as a magnetically separable and highly active catalyst for the Suzuki coupling reactions of various aryl halides with substituted phenylboronic acids. Under appropriate conditions, all reactions afforded the desired products in excellent yields at short reaction times. Moreover, this catalyst can be easily recovered by using a magnetic field and directly reused for five times in this cross coupling with good yield and suitable time. [GRAPHICS] .