Abstract. The generic polarized $K3$ surface (S, h) of genus 16, that is, (h^2)=30, is described in a certain compactifeid moduli space \mathcal{T} of twisted cubics in P^3, as a com plete intersection with respect to an almost homogeneous vector bundle of rank 10. As corollary we prove the unirationality of the moduli space \mathcal{F}_{16} of such K3 surfaces.