The cross-section and surface structures of wing membranes from the ctenochasmatid pterosaur Beipiaopterus chenianus were observed through a scanning electron microscope (SEM). The results show that the wing membrane contains a high density of blood vessels, implying strong thermoregulatory function, similar to that of a bat wing membrane. This is the first comparison of the microstructures of pterosaur wing membranes with those of the modern bat. It is inferred that a bat-like physiology exists, at least in relatively small pterosaurs suggesting that these pterosaurs were warm-blooded, active fliers.