This invention provides a nanocrystalline with high fluorescence luminous efficiency, comprising a core body and an outer shell layer. The core body has an inner core composed of at least ternary elements and has sphalerite crystal structure, and a doping element. Said constituent elements of the inner core are selected from IB group, IIIA group and the VIA group, and the doping element is selected from at least one of the IB group, the IIB group and the IIIA group, and the doping element is non-uniformly doped in the core. The outer shell layer covers the core and is composed of at least two elements, and these elements are selected from the IIB group and VIA group or IIIA group and VIA group. In addition, the present invention also provides a method for preparing the nanocrystalline. |