The frustration of triangular antiferromagnets with isotropic interactions leads to a variety of ground states even for classical spins. In regions where several classical phases are degenerate, quantum spins may realize a quantum ground state with lower energy. From symmetry analysis, 15 different types of quantum spin liquid ground states have been classified for the triangular lattice, symmetric spin liquids as well as chiral spin liquids. Recently a new polycrystalline spin 1/2 triangular antiferromagnet has been synthesized, CuSb2O6 in rosiaite structure, space group P-31m. The absence of long-range order of trigonal CuSb2O6 is the more intriguing as magnetization and susceptibility clearly indicate substantial antiferromagnetic correlations. In order to find out whether or not there is a static ordered moment, we would like to perform muSR experiment.