Eigenstructure assignment (EA) technique was utilized to design Airbus A320 lateral and directional control law, which provides advantages regarding to desired closed loop eigenvalue assignment and critical variables decoupling. Using Linear Quadratic (LQ) technique,this paper redesigns close loop gains based on the structure of A320 control law. Firstly, specific frequency shaping functions are incorporated with critical parameters based on the desired eigenvalue. Then performance index are adjusted to approach the desired eigenvalue and decouple the critical variables, and all gains are obtained simultaneously. Finally, the resulted eigenstructure, stability margins and decoupling performance between two axes critical parameters are compared with Airbus design which is based on EA technique. Analysis results show that a similar set of gains and closed loop performance can be obtained with LQ technique, i. e. the resulted eigenvalues are close to the designed ones, critical parameters are decoupled and good stability margins are ensured.