Aeroelastic phenomena including divergence and flutter are investigated for composite plate wing without sweep angle. Suitable derivations of aerodynamic loads have been developed for calculating both flutter speed (UF) and divergence speed (UD). Equivalent plate method is used for structural modeling of composite plate wing. Approximate solutions
from the linearized formulation are obtained for studying steady and unsteady aerodynamic loadings on harmonically oscillating wing in subsonic flow. The wing is divided into element panels on which lift distributions are represented by concentrated lift forces. The pressure coefficient distribution is calculated at root chord using steady and unsteady aerodynamic modeling. The span wise distribution of lift coefficient is calculated from the pressure coefficient. The numerical results for both UF and UD show good agreement with previous works. Finally a parametric study of the effect of composite fiber's orientation on both UF and UD is carried out.