From the study of the kinematics properties of the final state produced in the semileptonic $\mathrm{B}$ decays $\mathrm{B\to \ell\nu_{\ell} X}$, the inclusive charmless semileptonic branching ratio of $\mathrm{B}$-hadrons has been measured. Using the data collected between 1992 and 1995, one gets: $\mathrm{BR(B\to \ell\nu_{\ell} X_u)} = (1.6\pm 0.4_{stat}\pm 0.4_{syst})\times 10^{-3}$, where $\mathrm{X_u}$ represents any charmless hadronic states.