Objective To evaluate the value of diffusion-weighted imaging (DWI)in the diagnosis of focal hepatic lesions by quantitative analysis. Methods A total of 111 patients with focal hepatic lesions(including 35 cases of hepatocellular carcinoma, 7 cases of peripheral cholangiocarcinoma,25 cases of hepatic metastatic tumors,3 cases of focal nodal hyperplasia,22 cases of hepatic hemangiomas and 19 cases of hepatic cysts)were examined by MRI SE-EPI and DWI(b=500/mm2 ) sequence, to measure and analyze the difference of apparent dispersion conficient(ADC) values. Results When b=500s/ mm2 ,the average ADC value of normal hepatic tissue was(1.49±0.14)×10-3mm2 /s， the average ADC values of hepatocellular carcinoma、metastatic tumor、focal nodal hyperplasia、hemangioma and cyst were (0.93±0.14)×10-3mm2 /s, (0.97±0.15)×10- 3 mm2 /s, (1.06±0.17)×10-3mm2 /s, (1.53±0.29)×10-3mm2 /s, (2.18±0.23)×10-3mm2 / s and (3.15±0.21)×10-3mm2 /s. The ADC value of hepatocellular carcinoma and metastatic tumor lower than that of normal hepatic tissue(P＜0.001).The ADC value of hemangioma and cyst higher than that of normal hepatic tissue(P＜0.001).The ADC value had no significant differences between focal nodal hyperplasia and normal hepatic tissue, hepatocellular carcinoma (P＞0.05). Conclusion According to DWI and ADC values, the quality of hepatic lesions can be exactly diagnosed, which has a certain value in the diagnosis and differential diagnosis of focal hepatic leions.