Objective To analyze the CT and MRI findings and the prognosis of focal nodular hyperplasia(FNH). Methods 32 patients with FNH who were admitted to the hospital from September 2013 to September 2017 were included in the study. Their CT and MRI image data were analyzed retrospectively. The relationship between the location, size, shape and main signs showed by CT/MRI plain and dynamic enhanced scan and peripheral tissues was analyzed. Changes of density / signal in different periods were described. Results CT plain scan showed 10 cases with equal density, 22 cases with slightly low density and 14 cases with slight like, strip and star-like low-density central scar. Enhanced scan showed clear boundary, 30 cases with obvious enhancement in the arterial phase and no enhancement of central scar. There were 5 cases with obviously enhanced thickened tortuous artery in and around lesions, and different degrees of enhancement decrease in portal phase. 6 cases showed mild enhancement of the central scar, and continuous decrease of enhancement of substantial part in delayed phase. 14 cases showed delayed enhancement of central scar and slightly high-density expression. MRI plain scan showed 24 cases of high signal and 8 cases of equal signal on T2WI, 17 cases of slightly low signal, 12 cases of equal signal and 3 cases of high signal on T1WI. There were 12 cases of central scar in lesions, showing high signal on T2WI and low signal on T1WI. MRI enhanced scan showed similar signs with CT enhanced scan in arterial phase, portal phase and delayed phase. 8 cases showed central scar enhancement in portal phase, and 12 cases showed continuous enhancement in delayed phase, which was slightly high signal. Conclusion Both CT and MRI can accurately and comprehensively display the pathology and blood supply of FNH, which is of great value in the diagnosis and identification of FNH.