In this article, a novel two-port dual-band dual-circularly polarized slot antenna with diversity is designed for wireless application. The antenna consists of a square slot, two asymmetric T-shaped feed lines in orthogonal direction protrude from signal lines, and an arrow shaped grounded stub at the inner corner of the ground slot between the two orthogonal feed lines at an angle of 45ᵒ. Orthogonal feed lines are used for generation of circular polarized waves. If we apply the excitation at another port the sense of circular polarization is interchange in both the bands of axial ratio. The lower band of axial ratio covers frequency range of 1.42-2.25GHz with 45.23% and fc 1 =1. 85GHz.Same for upper band covers frequency range of 3.43–3.65 GHz with 6.22% and fc 2 =3.3GHz. The two ports of antenna have isolation variation from 10 to12 dB and 17 to 18dB in the lower and upper band of axial ratio. The proposed antenna has isolation between lower and upper bands of impedance bandwidth also.