In the fasting rat liver, the weight, the total protein content and the total lysosomal protein content were decreased at almost the same rate, they were 60 %, 55%, and 50% at l, 2,and 4 day fasting, respectively. The content of cystathionine γ-lyase per liver were decreased a little faster than the hepatic total protein, it was about 50% of control level at 1 day fasting, after that the decrease became slowly, and it was about 40 % of control level at 4 day fasting. The sequestration of cystathionine γ-lyase into lysosome were 35%, 15%, and 10% at 1,2,and 4 day fasting, respectively. These results indicate that the degradation of liver cystathionine γ-lyase are depresed in the fasting rats.