Abstarct: In this study, a cold atmospheric He plasma jet is investigated. This jet is of a dielectric barrier discharge type consisting of a dielectric tube with two mextal ring electrodes. The continuity, momentum and energy conservation equations as well as the Poisson equation for obtaining the potential and the electric field accompanied with the ideal gas laws are used for the simulation. The results show that electron density, potential, electric field, energy, temperature and the electron pressure increase with time. Moreover, the increment of the plasma length and its forward propagation along the jet axis with time is also observed. Therefore, it is expected that the values of the mentioned quantities increase with time which results in the increment of the plasma jet length