We present the analysis of UV and optical spectra of M 33 early B-type supergiants. Stellar parameters, metal abundances (Si, Mg, O and N) and mass loss rates are derived from anlyses of optical spectra by means of non-LTE unblanketed unified model atmospheres (fastwind code, Santolaya-Rey, Puls & Herrero 1997). These analyses use wind terminal velocities previously derived from the analysis of UV P-Cygni profiles. Stellar radial gradients of Si, O and Mg are derived for the M 33 disk. Differential abundances of those elements with respect to Galactic counterparts are also presented, along with nitrogen. Finally, the wind momenta of M 33 stars is derived and compared with the one found for Galactic B-type supergiants.