Absolute　phononic　band　gaps　can　be　substantially　improved　in　two-dimensional　lattices　by　using　a　symmetry　reduction　approach.　In　this　paper,　the　propagation　of　elastic　waves　in　a　two-dimensional　hybrid　triangular　lattice　structure　consisting　of　stainless　steel　cylinders　in　air　is　investigated　theoretically.　The　band　structure　is　calculated　with　the　plane　wave　expansion　(PWE)　method.　The　hybrid　triangular　Bravais　lattice　is　formed　by　two　kinds　of　triangular　lattices.　Different　from　ordinary　triangular　lattices,　the　band　gap　opens　at　low　frequency　(between　the　first　and　the　second　bands)　regime　because　of　lifting　the　bands　degeneracy　at　high　symmetry　points　of　the　Brillouin　zone.　The　location　and　width　of　the　band　gaps　can　be　tuned　by　the　position　of　the　additional　rods.