Abstract: A traffic cone assembly has a base, a telescopic unit and an illuminating unit. The base has an inner space and a base hole formed through a top surface of the base. The telescopic unit is capable of telescoping longitudinally, is securely connected with the base and has a bottom, a middle and a top. The bottom of the telescopic unit is securely mounted in the inner space of the base. The middle of the telescopic unit protrudes out from the base hole. An LED (light emitting diode) of the illuminating unit is securely mounted on the top of the telescopic unit. Because the LED mounted on the top of the telescopic unit can illuminate, the traffic cone assembly can be seen with good visibility.