Objective To discuss the value of the multi-b-value diffusion weighted imaging (DWI)in diagnosis of liver tuberculosis,abscess and atypical hydatid disease.Methods 23 patients with different liver lesions including abscess in 1 1,tuberculosis in 3 and alveolar hydatid in 9 were scanned with conventional MRI and multi-b-value DWI,and the imaging results were retrospectively analyzed.The ADC1 0b maps with 10 b values,three ADClow ones with low b values of 0 s/mm2 ,50 s/mm2 and 100 s/mm2 ,three ADChigh ones with high b values of 500 s/mm2 ,750 s/mm2 and 1 000 s/mm2 were gotten respectively.The ADCperf value was defined as a difference between ADClow and ADChigh values.Two regions of interest (ROI)with the same size were drawn in the liquefied region and mar-ginal area of the mass.The ADC values of ADClow ,ADChigh ,ADCperf and ADC1 0b maps were calculated and analyzed.Differences in b value and region among the three liver diseases were compared.Results The differences in ADC10b and ADChigh values between atypical liver hydatid and liver abscess in the liquefied region and marginal area were significant (P <0.05);the differences in ADC10b and ADCperf val-ues in the marginal area among liver tuberculosis,abscess and atypical hydatid were significant (P <0.05).The differences in ADCperf value in the liquefied region between thydatid disease and abscess,and in ADChigh value in marginal area between tuberculosis and abscess were not statistically significant (P >0.05).No differences in the ADClow value were found in both areas of three lesions (P >0.05). Conclusion Multi-b-value DWI and ADC maps and ADC values can provide valuable information in diagnosis and differentiation of liver tuberculosis,abscess and atypical hydatid disease.Different ADC values play more important role in the diagnosis of liver diseases.