The wet weight, lipid contents and the percentages of PL components of lung tissues, SAM and AM of normal, Silicotic and TT treated rats were analysed. It was indicated that the wet weight, lipid contents of lung tissues, SAM and AM of Silicotic rats all were increased, and with the lapse of experimental period. In lung tissues the percentages of PC, PG and PI accounted for the total PL were increased and PS, S were decreased in comparison with those of normal rats. The PL percentages in SAM of Silicotic rats were not significantly different from those of normal rats. The wet weight, lipid contents of lung tissues, SAM and AM, percentages of PL components in lung tissues of TT treated rats were higher than that of normal rats and lower than that of silicotic rats. The percentages of PC, USPC accounted for the total PL in SAM of TT treated rats were lower while PI, PS,S were higher than that of normal and Silicotic rats. The other percentages of PL components were not significantly different from that of normal and silicotic rats.