<正>Two-frequency laser has wide uses in new laser interferometer.The study of Zeemaneffect and mode competition effect for that laser is much important in practice as wellas in theory, but it has not been reported up to now. In this paper, we have studiedthese problems both theoretically and experimentally. At first, we have calculated theanomalous Zeeman splitting of Ne atom. The results show that, Lande g-factors are