Abstract: A flutter differential equation for two coupled asymmetrical control surfaces was derived usingLagrangian equation under the supposition of quasi-steady aerodynamic forces. Examples were presented to analyze the effectsofasymmetricalparameterson the critical fluttervelocityunderdifferent coupled stiffness. The results show that the asymmetry of structural parameters is beneficial to the increase in fluttervelocity; butwhen the values ofasymmetricalparameters are large enough to change the fluttercharacteristicsof the system, the asymmetricalparametersmightnot increase fluttervelocity.