The mechanism of C-13-methacetin breath test is set forth clearly with
the analysis of pharmacokinetics mode, and the measuring method of C-
13-methacetin breath test and its clinical applications in the diagnos
is of liver diseases are reported in detail. On the basis of comprehen
sive analysis of the clinical test data, the advanced diagnostic param
eter S is of important significance for the application and developmen
t of breath test.