Dust layers in the free troposphere were observed with the lidars in Suwon, Gosan, and Tsukuba in March 7-9, 2005. The observed dust distributions were compared with the results of the regional and global dust transport models (CFORS, NRL NAAPS, and SPRINTARS). The results with the global models reproduced the dust layer qualitatively, but the regional model did not. This suggests the source of the dust layers is located outside of the modeled region of the regional model that includes Taklimakan Desert and Gobi Desert. The global models showed the plumes were from the Sahara Desert, and the both models showed there was no major dust emission in Taklimakan and Gobi Deserts during the observation period. The trajectory analysis using NOAA HYSPLIT showed that the dust originated in the Sahara Desert 5-10 days before.