Factor analysis of hepatobiliary scintigraphy using 99mTc-N-pyridoxyl-5-methyltryptophan (99mTc-PMT) was performed, and functional factor of liver parenchyma (FA-hepatogram) was obtained. Two parameters (peak time, T 1/2) were calculated from this hepatogram. A good correlation was obtained between these parameters and ICG-R15; furthermore, these parameters were prolonged in patients with normal volunteers, chronic hepatitis, compensated and decompensated liver cirrhosis in this order. Conventional hepatogram by ROI method (ROI-hepatogram) was not suitable for the evaluation of global liver function in condition such as a large intrahepatic mass, intrahepatic gall bladder, dilatation of biliary tree, and severe liver cirrhosis. But, even in such cases, FA-hepatogram was useful for the evaluation of global liver function.