Borehole gravity is an effective method for directly imaging anomalous mass distributions at large depths, and it has braod applications in mineral and petroleum exploration and production. The method was presently limited to vertical gravity data only. The anticipated development of vector gravimeters may change this scenario dramatically. There was a need to understand the potential capability of vector gravimetry and to develop corresponding modeling and interpretation techniques. We introduced a set of numerical modeling tools for vector gravity and examined the relative information content of vertical and vector gravity data in borehole environments. Through simulations, we illustrated that vector gravity was superior to vertical gravity in applications such as locating and characterizing anomalous mass and in tracking the movement of fluid injection in reservoirs.