Water vapor is an important component of terrestrial atmosphere, which attenuates infrared radiance in the atmosphere and affects optical-electron engineering capability. The 940 nm channel of sun-photometer was calibrated by modified Langley method. According to the relationship between atmospheric transmittance and water vapor amount, the precipitable water vapor(PWV) was measured with ground-based microwave radiometer in Hefei, Anhui and Kashi, Xinjiang regions. The results showed that the PWV retrieved by these methods agrees with each other, the relative percent difference in the retrievals is less than 5.1%. The daily PWV retrievaled by microwave radiometer agreed well with the sun-photometer.