Abstract: By adding a inhomogeneous longitudinal magnetic field in the laser cavity, two kinds of the single self-stabilized-frequency He-Ne lasers have been developed.The lasers have the features of the external cavity configuration and high power out-put.Without any external frequency stabilization device, the frequency stability can reach to 6.175×10-9(τ≤10s),3.38×10-9(τ-8 (τ-8(τ<1s) for 1.8 meter laser, measured by beat frequency method.From these facts and hmogeneous extension of spectral line of high pressure gas laser, this paper analyzes the basic principles of the self-stabilized-frequency lasers and point out that this method is simple and can be widely used in the measurement devices.