We propose a large N vector quantum mechanics as the theory describing a D-particle probe in bubbling supertube solutions. We compute the effective action of this quantum mechanics and show that it coincides with the D-particle action in a certain decoupling limit, up to quadratic order in the velocity. The angular momentum of the D-particle, including the contribution of the Poynting vector, is reproduced as the vacuum expectation value of the SU(2)R typeset using PTPT E X.cls Ver.0.9 * ) Here we use the term "particles" in the four-dimensional sense. From the viewpoint of fivedimensional spacetime, it means two different kinds of objects: CG centers and rings.