Abstract: Based on Hopf bifurcation, the behavior of limit cycle wing rock motion resulting from new couple of effects including dihedral effect derivative and directional stability derivative is presented in this study. To demonstrate the behavior of limit cycle oscillation and the divergence influence of state variables, a complete set of aircraft nonlinear equations of motion including these effects is solved. A candidate mechanism for the wing rock limit cycle is the inertia coupling between an unstable lateral-directional (Dutch roll) mode and a stable longitudinal (Short period) mode. The coupling mechanism is provided by the nonlinear interaction of motion related terms in the complete set of motion equations. The numerical results indicated that the situation of wing rock dynamics becomes more and more critical (divergent influence of roll and sideslip angles) as dihedral effect derivative increases and directional stability derivative decreases. The results also show that dihedral effect is the most significant stability derivative in the determination of wing rock dynamics. Furthermore, the weak influence of roll damping upon the behavior of limit cycle oscillation is demonstrated based on the method presented. A good agreement between the numerical results and the published work is obtained for limit cycle oscillation existence at different values of damping ratio.