Water vapor is one of the basic atmospheric parameters, and the vertical structure of the atmosphere is of great importance to process studies. Differential absorption lidar is the techniques which provide high resolution and accuracy for water vapor profiles daytime and nighttime, and that is the most potential instrument. Differential absorption lidar (DIAL) operates in the 720~730 nm region of the 4ν overtone vibrational bands of H2O where previous using tunable dye, or Alexandrite ring laser injection seeded, however, photomultiplier acts as detector. The represent is airborne lidar LEANDRE II. And the DIAL transmitter is based on an injection-seeded, Ti:Sapphire laser or Ti:Sapphire amplifier operated at 820 nm, Si-APD act as detector. University Hohenheim mobile lidar can perform the measurements of the 3-dimensional structure of the water vapor field from 300 m to 4 km altitude. The high-power DIAL at the Schneefernerhaus research station has successfully demonstrated its measurement capabilities of vertical structure of water vapor from 3 to 12 km above sea level. The development of an OPO at 935 nm in the spectral region of the 3ν overtone vibrational band of H2O was stimulated by the need to develop an airborne water vapor DIAL with high measurement sensitivity at tropopause height, particularly in case of very dry air from the lower stratosphere. In this 935 nm wavelength range, the line strengths of suitable water vapor absorption lines are more than a magnitude higher than near 720 nm or 830nm. Based on single-frequency, a diode-pumped Nd∶YGG laser system or optical parametric oscillator emitting at 935 nm, differential absorption lidar has recently been developed to space borne measures water vapor profile of upper troposphere/lower stratosphere (UTLS) region. DBR diode laser and semiconductor optical amplifier as transmitter, APD as Geiger counter, micro-pulse DIAL for measuring water vapor in the lower troposphere has been developed and validated at field campaigns, and the fourth generation product has been constructed and tested. The application required a single-frequency laser transmitter operating at near infrared region of the water vapor absorption spectrum, capable of being on/off wavelength seeded and locked to a reference laser source for DIAL measurements. The system is based on extended-cavity diode lasers and distributed-feedback lasers. It is achieved by locking the laser wavelength to a water vapor absorption line using compact water-vapor reference cells. or the wavemeter readout for frequencies of laser1 or laser 2 counts as the error signal, product of the error signal and the PID adds as a correction to the applied voltage on the piezo controllers and injection current to tune more stably and smoothly frequencies of the diode laser. Second, precise knowledge of spectral properties of water vapor absorption, laser emission, and atmospheric scattering is necessary. However, to get high accuracy one has to consider methods of treating the problem of Doppler-broadened Rayleigh back scattering and correcting absorption section of water vapor in DIAL experiments. At last, the backscatter signal in the near-field channel rapidly drops to a level at which the results are affected by noise and electromagnetic interference. So the matching of near- and far-field channels in the lower part of the operating range with both detection channels is necessary.