An experimental study is presented of a cold atmospheric plasma jet with high plasma stability. To improve the performance of the plasma jet effectively, a coaxial-type electrode and a ground electrode of the variable position are applied. The discharge characteristics and stage evolution in different positions of ground electrode are measured, and the relationship between the position of ground electrode and the initial voltage of plasma jet is shown as a parabolic curve. The lowest point of the curve and the front end of the high voltage electrode are in the same plane, and the maximum range of the stable stage is also located in this position.