In present paper electromagnetic wave has been studied in the presence of parallel A.C. electric field for pitch angle loss-cone anisotropic magneto-Plasma. The detail derivation of dispersion relation and growth rate has been done by using the method of characteristics solution and kinetic approach. The effect A.C field frequency and magnetite of A.C. field has been studied and discussed in the result section. The pitch angle anisotropy is the prime source of instability.
