We observed the charge reversal of microbubble-polyelectrolyte complexes using microscopic electrophoresis. The measured mobility of microbubbles with the addition of cationic poly(allylamine hydrochloride) exhibited unusual behaviors. The critical concentration of polyelectrolytes added for the charge reversal was not only weakly dependent on chain length but was also much larger than that of colloidal silica-polyelectrolyte complexes. We attribute the nonstoichiometric overcharging to the adsorption-desorption kinetics of hydroxy ions on the surface of genuine microbubbles.