A resin composition is provided. The resin composition comprises the following components: (a) a thermal-curable resin system, which has a dielectric loss (Df) of not higher than 0.008 at 10 GHz and comprises a bismaleimide resin of the following formula (I), wherein M1 and the Z1 groups are as defined in the specification; and (b) an organic compound of the following formula (II) or formula (III), wherein R′, R11 to R19 and R21 to R28 are as defined in the specification, and wherein the amount of the organic compound (b) ranges from 1 wt % to 30 wt % based on the total weight of the resin system (a) and the organic compound (b).