cadmium chalcogenide had been intensely studied since the 1980s, [4] its toxic character limited its wide application, and the IB-IIIA-VIA 2 semiconductors had been regarded as the promising alternatives for Cd-free chalcogenide nanometeirals. [3] Among IB-IIIA-VIA 2 materials, the AgInS 2 nanostructures with direct band gap exhibited strong photoluminescence (PL) in the visible-light wavelength region and had attracted extensive attention in recent research. [5][6][7][8][9] Moreover, it was found that the PL properties of AgInS 2 nanostructures were strongly influenced by the defects, such as the non-irradiative recombination of excited carriers trapped by surface defects (e.g., the dangling bonds on the nanomaterial surface), or the donor-acceptor levels and/or surface traps resulted in the defect emission, [10,11] which was characterized by the large stokes shift and broad emission spectrum. For the application of AgInS 2 nanostructures, how to eliminate defect emission and enhance band edge emission was a very important topic. Recently, it had been reported that coating the IIIA-VIA group semiconductor (e.g., InS x or GaS x ) on AgInS 2 core could remove the defect emissions and generate intense narrow band-edge emission of AgInS 2 . [7,9,12,13] Besides, using the organic ligands such as the trioctylphosphine to modify the surface of the AgInS 2 nanoparticles could also improve its band-edge emission, which could be attributed to the irradiative carrier trapping sites passivated by trioctylphosphine bonds. [14] Developing new strategy for synthesizing AgInS 2 nanostructures with the band-edge emission is challenging and significant for their wide application in optoelectronics.The AgInS 2 existed in two crystal forms, including the metastable orthorhombic phase usually formed above 620 °C and the stable tetragonal (chalcopyrite) phase formed below 620 °C, with the bulk bandgaps of 1.98 and 1.87 eV, respectively. [15] The AgInS 2 could be synthesized using various precursors via many methods, including hot injection and thermo-decomposition using the molecular organic metal precursors, [7,9,16] partial cation exchange using the binary Ag 2 S nanoparticles and molecular In 3+ -precursor, [17] reaction of the Ag 2 S nanoparticles as the source-host with In-S precursor, [18] and partial cation exchange using the binary In 2 S 3 nanocrystals and molecular Ag + -precursor. [19] Actually, in the hot injection A deep understanding of the growth kinetics and mechanism of metal sulfide nanostructure is helpful in preparing nanomaterials with controllable structures.