A resin composition is provided. The resin composition includes a thermosetting resin component and a filler, wherein the thermosetting resin component has a dissipation factor (Df) of not higher than 0.006 at 1 GHz, and the filler is selected from the following group: strontium titanate, calcium titanate, barium titanate, magnesium titanate, combinations thereof and the sintered material of any of the combinations. The filler is doped or not doped with one or more elements selected from silicon, cobalt, nickel, manganese, and rare earth elements. The average particle size (D50) of the filler ranges from about 2 μm to about 10 μm. The amount of the filler is about 10 parts by weight to about 600 parts by weight per 100 parts by weight of the thermosetting resin component.