Merits and demerits of three kinds of methods for measurements of hepatocyte growth-promoting factor (HGF) activity were compared. With human hepatoma HepG2 cells as materials, the bioactivity of HGF was detected by 3H-TdR incorporation, tetrazolium bromide (MTT) colorimetry and trypan-blue exclusion test XTT/PMS, resp. Linear correlation coefficient (r), the maximum stimulation index (SI) and operation simplicity of the three methods were compared. Both the sensitivity (SI=3.65) and the accuracy (r=0.91) of the MTT method were poor. The sensitivity of the XTT/PMS method (SI=23.19) was not as good as that of the 3H-TdR method (SI=23.19), but its accuracy (r=0.98) was the best, with the most simple operation. After adjustment by the standard, the XTT/PMS method can be the first choice for the routine measurement of the HGF activity.