Tight binaries discovered in young nearby associations are ideal targets to provide dynamical mass measurments through orbital monitoring. Coupled with estimated temperatures, surface gravities and luminosities, direct mass measurments provide benchmarks for evolutionary models of low-mass stars (M ≤ 0.5 M๏) and brown dwarfs (M ≤ 0.078 M๏) at young ages (Age ≤ 100 Myrs). TWA22 AB is likely to be a member of the nearby TW Hydrae association (Age ~ 8 Myr). It was resolved in a tigh binary with a projected separation of a few AU. In this paper we present preliminary results on the companion orbital monitoring and on the spectral characterisation of the system.