Thieno[3,2-b]thiophene represents a typical core structure in a large number of organic optoelectronic materials. In this paper, we present a facile route to precisely functionalize of 2,3,4,6-tetrabromothieno[3,2-b ]thiophene by the siteselective Suzuki cross-coupling reaction with boronic acids. Based on this procedure, a number of mono-, di- and tetraarylthieno[3,2-b]thiopheneS were prepared with good yields. NMR and X-Ray analysis indicated a high regioselectivity at the C-2 and C-5 positions of the fused ring skeleton.