As the basic study to elucidate the influences of chemotherapy on the liver function in lung tuberculosis the author summarily conducted various clinico-chemical examinations of the liver function in 126 cases of lung tuberculosis and studied the disturbances of the liver function in this disease. 1. Changes in the serum protein picture is especially marked, and by a decrease in albumin with the proportionate increase in globurin the rate of the decrease in A/G reaches as much as 52.4 per cent, showing in addition a significant correlation between the serum protein picture and the clinical of lung tuberculosis. 2. There is a significant mutual relationship between the clinical symptoms of lung tuberculosis and results of various examinations such as Gros' reaction, Takata' reaction, CCF, Ch-E and TTT tasts, revealing a high degree of disturbances in the liver parenchym in the advanced exsudative and open cases. 3. The case showing a rise in the icteric index is extremely rare, and there is not a single case that presented icteric sign as the result of the estimation of total bilirubin, cholesterol, and alkaliphosphatase. 4. Looking over the entire cases, the disturbances in the liver function have been recognized in 23.8 per cent; namely, 12.7 per cent in the minimal cases; 29.2 per cent in the moderately advanced cases; and 45.5 per cent in the far advanced cases. Although there is a mutual relationship between symptoms and the liver disturbance, there can be found not one case showing a critical disturbance. 5. From these results it is believed that the functional disturbance of the liver in lung tuberculosis is a mild symptom consisted mainly of the disturbance in the protein metabolism, caused by the chronic infection. 6. As for the routine work in the examination of the liver function in lung tuberculosis it is justifiable to conduct examinations of the serum protein picture, especially the picture of albumin and A/G, Gros' reaction, Takata' reaction, CCF, and Ch-E or TTT tests, and BSP test if necessary. It is moreover advisable to examine the icteric index for detection of the icteric sign, and to estimate the quantity of total bilirubin, cholesterol and alkaliphosphatase if necessary. 7. Although the results of such examinations are not specific to the lung tuberculosis, it is considered that the all-round examination has an extremely significant bearing on the accurate prognosis as these results coincide well with the intensity and progress of the disease.