Various bubble jet flows induced by thermocapillary force were found during sub-cooled boiling on heated wires，and strong jet flows usually existed above very small bubbles，while the jet flow direction was normally dependent upon local conditions.Both jet flow structure and flow field were visually observed and explored by using small particle tracing technology，and the jet flow behavior and dynamic characteristics were discussed together with the experimental measurements.The bubble jet flow was divided into three regions，namely pumping region，neck region and expanding region.The bubble near jet flows was observed to act as a cold source，which prominently affected the adjacent jet flows due to the thermocapillary effect.The bubble jet flows nearby had attractive interaction due to the thermocapillary force and bubble sink，and two bubble jet flows would combine into one jet flow due to strong interaction.During bubble departing，the adjacent bubble jet flows experienced an unsteady evolution.