The deuteron spin dependent structure function $g^{d}_{1}$

Results on the deuteron longitudinal inclusive spin-dependent asymmetry $A^{d}_{1}$ and the spin-dependent structure function $g^{d}_{1}$ are presented. The data have been collected by the COMPASS experiment at CERN during the years 2002-2004 using the 160 GeV/c polarised muon beam scattered off a polarised $^{6}$ LiD target. The values obtained for $\Gamma^{d}_{1}$, the first moment of $g^{d}_{1}(x)$, and the flavor-singlet axial current matrix element, $a_{0}$, are also shown. The results of QCD fits in the NLO approximation on all $g_{1}$ deep inelastic data are presented.