Disclosed herein is a method for manufacturing metal sulfide nanocrystals using a thiol compound as a sulfur precursor. The method comprises reacting the thiol compound and a metal precursor in a solvent to grow metal sulfide crystals to the nanometer-scale level. Further disclosed is a method for manufacturing metal sulfide nanocrystals with a core-shell structure by reacting a metal precursor and a thiol compound in a solvent to grow a metal sulfide layer on the surface of a core. The metal sulfide nanocrystals prepared by these methods can have a uniform particle size at the nanometer-scale level, selective and desired crystal structures, and various shapes.