The structure of respiratory system and respiratory behaviors of Luciola leii larvae were studied. The results showed that there were only tracheas without air sacs in the whole respiratory system of L. leii larvae. The spiracles were located on prothorax, mesothorax and metathorax, where no tracheal gills were distributed. Both the spiracles and tracheal gills were located on the 1st～8th segments of abdomen and tracheal gills connected with the basement of the atrium which formed the shape of “∨ ". The tracheas in the tracheal gills connected with the spiracular trachea. L. leii larvae had three kinds of respiratory behaviors:  using thoracic spiracles, abdominal spiracles and tracheal gills to breathe, in which the abdominal spiracles were primarily used.