The reconstruction patterns of Si- and C-terminated surfaces of wurtzite SiC are studied by ab initio molecular dynamics. The (1×1) relaxed, (1×2) buckled, and (2×1) л-bonded chain geometries are considered. In the (l×1) geometry, inward relaxation of the C-terminated surface is much stronger than that of the Si-terminated surface. The C-terminated surface is stable with respect to (2×1) buckled reconstruction, but the Si-terminated surface is not. At both surfaces, the (2×1) л-bonded chain geometry is energetically the most favorable. The Si-C л-bonded chains are buckled and slightly dimerized. In both cases, the outermost atoms are carbons, due to the bond length constraints of the л-bonded chain reconstruction.