A wireless device for selecting a connection target based on signal quality, a system and a method thereof are provided. The invention selects a candidate device having the best signal quality and duration of the signal quality is not less than a threshold reaching a certain time. If the selected candidate device also selects the wireless device, a unique connection is established between the wireless device and the candidate device. In a dynamical and complicated environment, the disclosed system and the method can build up a stable linear topology through automatic negotiation among wireless devices. The invention then achieves the effect of updating topology in time to adapt to environment changes.