The invention relates to a method for producing semiconductor nanocrystals with a core-shell structure and the semiconductor nanocrystals obtained by the method, which enables continuous production in a compact system. The method includes (1) passing a stock solution of a core component such as CdSe through a first hollow microchannel having an inner diameter of 1 to 1000 μm at a predetermined constant flowrate to form cores at 250 to 350° C., (2) passing a stock solution of a shell component such as ZnS through a second microchannel, and (3) passing the core stream merged with the shell component stream through a third microchannel at a predetermined constant flow rate to epitaxially grow the shell component on the cores at 100 to 250° C. to thereby form a core-shell structure. The microchannels communicate with each other, and step (3) is performed consecutively with steps (1) and (2).