A turn signal on a front-fork shock-absorber includes a shock-absorber fixed on the front-fork of the front wheel of a motorcycle, and a light emitter fixed in a recessed space formed on an outer surface of a hollow housing fitted around the front-fork rod. A light penetrable plate is closed on the recessed space, and the light emitter is connected by wires also connected with the circuit of the turn signals of a motorcycle after the wires extends through the hollow housing and through a tube route in the front-fork rod. So the light emitter is lit up blinking and synchronously with the turn signals of the motorcycle for making up an auxiliary warning for boosting traffic safety.