Abstract: The middle atmospheric density, pressure and temperature structure was measured by 532 nm and 355 nm Rayleigh Scattering Lidar between the altitude 25 km and 40 km at Hefei(31.90N; 117.170E), respectively. 532 nm Rayleigh Scattering Lidar system adopted Nd:YAG laser of 532 nm and 400 mm Cassegrain telescope. 355 nm Rayleigh Scattering Lidar system which was improved on the basis of 532 nm Rayleigh Scattering Lidar system, employed Nd:YAG laser of 355 nm and four Cassegrain telescopes of 400 mm. According to experimental comparison, it could obtain that the SNR of 355 nm Rayleigh Scattering Lidar is more than 532 nm Rayleigh Scattering Lidar of about 6 times. The fluctuation of the density ratio and pressure ratio of 355 nm Rayleigh Scattering Lidar to Sounding Balloon are less than the fluctuation of 532 nm Rayleigh Scattering Lidar. The temperature biases between 355 nm Rayleigh Scattering Lidar and the sounding balloon of that day are about -2.14 K, and the maximum deviation is about 6 K. And the temperature biases between 532 nm Rayleigh Scattering Lidar and the sounding balloon of that day are about -6.98 K, and the maximum deviation is about 9 K. The results of comparative test for 355 nm Rayleigh Scattering Lidar and 532 nm Rayleigh Scattering Lidar have shown that the detection precision of 355 nm Rayleigh Scattering Lidar was higher than 532 nm Rayleigh Scattering Lidar, and the performance of 532 nm Rayleigh Lidar is better than 532 nm Rayleigh Lidar.