Using a continue-wave semiconductor laser as transmitter and a charge-coupled device (CCD) with a fish-eye lens as detector, a set of polar nephelometer is designed for measuring angular distribution of light scattered by atmospheric molecular and aerosols. The device can observe the scattering image of the atmospheric sample in real time, the scattering angle observation range is 14°-162°, and the polarization angle observation range is 0°-360°. We use this device to observe pure nitrogen and water vapor in real time seperately, then obtain their scattering images. The nitrogen scattering light shows good correlation with Rayleigh scattering theory and the linear fitting R-square of sacattering intensity varied by polarization angle with calculation is 98%. The variation trend of water vapor scattering light with scattering angle is in good agreement with Mie scattering theory. The results show that the device has potential application value in quantitative observation of aerosol scattering light.