The violent eruption of Philippine volcano Pinatubo in mid June of 1991 caused a serious perturbation on the stratospheric aerosols for a long period. In the paper, we report L625 lidar observational results in the period of 1991-1996, including evolution of volcano Pinatubo cloud. The time variation and vertical distribution of the volcanic cloud height, thickness, peak scattering ratio, and integrated backscattering coefficients will be analyzed. L625 lidar measurement data of stratospheric aerosol reveal the characteristics of background period before the volcanic eruption, the evolution of the Pinatubo volcanic cloud, and present new background level.