ABSTRACT. In this paper, we consider a coupled system of mixed hyperbolic-parabolic type which describes the Biot consolidation model in poro-elasticity. We establish a local Carleman estimate for Biot consilidation system. Using this estimate, we prove the uniqueness and a Hölder stability in determining on the one hand a physical parameter arising in connection with secondary consolidation effects λ * and on the other hand the two spatially varying density by a single measurement of solution over ω × (0, T ), where T > 0 is a sufficiently large time and a suitable subbdomain ω satisfying ∂ω ⊃ ∂Ω.