This paper theoretically investigates the microwave transition spectrum of 87 Rb atomic D1 line with specially prepared atomic state in a Hanle configuration.The approximate analytical results have shown that the 0-0 transition spectral line has the highest contrast and can be applied to microwave frequency standards. This paper theoretically investigates the microwave transition spectrum of 87 Rb atomic D1 line with specially prepared atomic state in a Hanle configuration. The approximate analytical results have shown that the 0-0 transition spectral line has the highest contrast and can be applied to microwave frequency standards. .