The purpose was to develop phantoms mimicking the viscoelastic properties of healthy and fibrotic livers. Three plastic phantoms composed of different concentrations (from 40% to 60%) were characterized at 60 Hz using Magnetic Resonance Elastography (MRE) tests. In parallel, the functional behavior (elasticity and viscosity) of healthy (N = 10) and fibrotic (minor: N = 20 and major: N = 10) livers were determined with MRE. The same MRE protocol (driver, frequency, MR sequence) was used for in vivo and in vitro experiments. MRE post-processing was realized with two methods allowing for the local measurement of the mechanical properties (shear modulus: µ) and the global analysis of the viscoelastic behavior through cartographies of storage (G') and loss (G'') modulus. The results showed an increase of the viscoelastic (G', G'') values as a function of the plastic concentration and as a function of the fibrosis level. The phantoms made of 40 %, 50 % and 60 % showed similar elastic properties of healthy (F0), minor (F1-F2) and major (F3-F4) liver fibrosis, respectively. This study has demonstrated that the developed phantoms could mimic the functional properties of healthy and fibrotic livers.