The large-scale regular silver triangular nanoplates were synthesized by the reduction of silver nitrate with sodium borohydride in the presence of sodium citrate and dioctyl sulfosuccinate sodium salt (AOT) and in the water bath. The morphologies of silver triangular nanoplates were studied by transmission electron microscopy, high resolution transmission electron microscopy and atomic force microscopy and X-ray diffraction. The optical properties were studied by UV-visible—infrared photospectrometery. The results confirm that the silver nanoplates are the single crystallinity with regular arrangement of atoms. The optical in-plane dipole plasmon band of the silver nanoplate has been extended to about 1230 nm, which is in the near-infrared (NIR) regime. Studies from different AOT concentrations, pH values and reaction time demonstrate that triangular nanoframe-mediated growth mechanism is supported only in the proper experimental conditions.