Abstract: The paper has founded the 2D model of plasma antenna and JE convolution Finite-Difference Time-Domain (JEC-FDTD) algorithm is applied to the study on the antenna scattering characteristics based on the model. The effects of plasma density, collision frequency and glass tube on the Radar Cross Section (RCS) of the plasma antenna were analyzed in the paper. The analyze results show that RCS of plasma antenna can greatly decrease with the collision frequency increasing and plasma density decreasing. On the other hand, when the plasma antenna work at high frequency, the glass tube also has impact on the antenna scattering characteristics. Accordingly increasing in thickness of glass tube and enlargement of permittivity of glass will make RCS of the antenna decrease. So the stealth performance of plasma antenna can be improved by choosing the suitable plasma parameter and materials of glass tube based on the work frequency.