The 6H BaRu 1− x Mn x O 3 with the hexagonal BaTiO 3 structure was synthesized using high-pressure sintering method. It is found that the lattice parameter deviates from Vegard's law at x=0.3 for the solid solutions due to the charge transfer effects at B-site. The substitution of Mn for Ru cations gives rise to the short-range magnetic ordering, due to the disordered arrangement of Ru and Mn cations. The compounds are weak ferromagnetic in the x range 0.05–0.40, with the maximal Curie temperature T c 175.2K at x=0.10. They are of spin-glass-like magnetism at lower temperature at x⩾0.1. With Mn doping, the 6H BaRuO 3 transforms to a semiconductor from the primal metal at x=0.30. The resistance as a function of temperature below about 70K follows the two-dimensional variable-range hopping conduction mechanism in BaRu 0.50 Mn 0.50 O 3 .