The results of lidar sensing of the lower atmosphere in the tropical zone of the Indian Ocean are described. Analysis of lidar data has made it possible to reconstruct and interpret the altitude structure of the atmospheric boundary layer and to follow its nighttime evolution. It is shown that the relative time variability of lidar returns enables one to differentiate in the convective atmospheric boundary layer the condensation level and the inversion layer, to which its maxima in the vertical behavior correspond. The behavior of deviations from the smoothed in time lidar returns has revealed the presence of characteristic zones with reduced negative values in the vicinity of clouds, which can be interpreted as zones of descending motions or the regions of air entraining from the free atmosphere over the inversion. The connection of signal anomalies in the atmospheric boundary layer of 100-300 m and at overlying levels has been followed.