The invention discloses a decorative bulb and a decorative lampstring . The decorative bulb comprises a lampshade, a lamp holder, a light source device, a power source device, a lampshade base and a lamp holder base, a mounting part is inserted into the lampshade base, the lamp holder base is inserted into the lamp holder, the power source device comprises a wire, and the lampshade base and the lamp holder base are each provided with a through hole allowing a wire to penetrate through; and the decorative lamp string comprises a main cable, a plurality of bulb holders and a plurality of decorative bulbs, and the decorative bulbs and the bulb holders are arranged in a one-to-one correspondence mode. According to the decorative bulb, a traditional auxiliary cable is replaced with the wire, when the lamp string is stored, the situation that the auxiliary cable and the main cable are knotted cannot be caused, the wire is arranged on the decorative bulb, the lamp string is easier to store, and meanwhile when the main cable is produced, the cost is lower, and the process is simpler; and the decorative lamp string is lower in production cost, long in service life and attractive and elegant in appearance, and meanwhile, the lamp string provided with the decorative bulbs is suitable for more occasions and is more interesting.