We present a theoretical study of the effects of solvent on the phase behavior of AB(n) miktoarrn star copolymer solutions by adopting the self-consistent mean-field (SCMF) theory. In general, the associated effects with the addition of one solvent on the AB linear diblock copolymers hold true on the AB(n) miktoarm star copolymers. However, due to the asymmetry of molecular architecture, AB exhibits a new spherical packing order of A15, which has to be considered in competition with the well-known body-centered cubic (BCC) and face-centered cubic (FCC) packing orders in the AB linear copolymer solutions. It is found that for A-formed spheres, the "normal" ones (i.e., formed when A is a minor block) can adopt two packing arrays of BCC and A15, while the "inverted" ones (i.e., formed when A is a major block) favor the A15 and FCC packing. Upon increasing the solvent amount/solvent selectivity, these A-formed inverted spheres tend to pack from BCC to FCC. Moreover, the transition of BCC/FCC -> A15 with increasing the solvent selectivity is often induced by the fact that a greater degree of the interfacial distortion from a round into the polygonal shape in order to relax the stretching penalty for the B arms on the outside domains. On the other hand, as to the B-formed spheres, we do not observe any stable region of the A15 phase, but only BCC and FCC. This is mainly attributed to the tension of the highly stretched B within the inner domains, thus the AB interface tends to preserve a more spherical shape. In this case, we observe similar solvent effects on the stability of BCC and FCC packed spheres, as those in the AB linear diblock solutions.