We discuss recent theoretical works on three different frustrated magnets. First, we consider Vanadium oxyfluoride that realizes an anisotropic Kagome lattice. Possible spin liquid phases are discussed and the comparison to isotropic Kagome lattice system is made. Secondly, we investigate generic spin exchange interactions in the three-dimensional Hyper-Kagome lattice system, Na4Ir3O8, and obtain a magnetic phase diagram. This is discussed in light of recent experiments on Na4Ir3O8. Thirdly, the magnetic properties of pyrochlore iridate films are examined. Different roles of the boundary and bulk electronic states are pointed out.