Abstract. Let M be a smooth real hypersurface in complex space of dimension n, n ≥ 3, and assume that the Levi-form at z 0 on M has at least (q + 1)-positive eigenvalues, 1 ≤ q ≤ n − 2. We estimate solutions of the local∂-closed extension problem near z 0 for (p, q)-forms in Sobolev spaces. Using this result, we estimate the local solution of tangential Cauchy-Riemann equation near z 0 in Sobolev spaces.