The Uniphase 1007 type long lifetime commercil He-Ne laser is studied as Zeeman frequency stabilized laser. A frequency drift of 5×10-9 is obtained by the maximum error analysis method for the observation period of 17 hours. The seperation between two linear polarizations of two frequency components of the laser output beam is 1/60. The orthogonal angle between two linear polarizations of the laser beam is 89.5°. The experimental adjustment technique of Zeeman laser is given. A physical phenomena is discribed on the relationship between polarizations of laser beam and number of longitudinal modes.