For a general vector-valued function $u$, we have the decomposition $u = curl w + abla p$. We proved the existence and uniqueness of $u$ when its vorticity, divergence and normal trace are prescribed in the unit ball of $bR^3$ under the assumption that the solvability condition holds. We start from solving for the velocity for the case that the domain under consideration is $bR^3$ or $bR^3_+$, and learn from this experience to provide another approach of constructing the solution and prove a regularity theory similar to the elliptic regularity theory.