Magnetic properties and magnetocaloric effects of Tb6Co1.67Si3 have been investigated by magnetization measurement. This compound is of a hexagonal Ce6Ni2Si3-type structure with a saturation magnetization of 187 emu/g at 5 K and a reversible second-order magnetic transition at Curie temperature TC = 186 K. A magnetic entropy change is found to be 330 J/kg for fields ranging from 0 to 5 T. The large RC, the reversible magnetization around TC and the easy fabrication make the Tb6Co1.67Si3 compound a suitable candidate for magnetic refrigerants in a corresponding temperature range.