Over the past decade, considerable interest has been given to the II–VI nanostructured semiconductors because of their important nonlinear optical properties, luminescent properties, quantum size effects and other important physical and chemical properties [1–7], and much progress has been made in the synthesis and characterization of these materials [8–10]. ZnS is a II–VI semiconductor with a large direct band gap in the nearUV region, and ZnS has many uses in blue light emitting diodes, electroluminescent displays, cathodoluminescent displays and multilayer dielectric filters, light guiding in integrated optics, IR antiflection coatings and solar cell [11, 12]. It has been shown that the sizes of particles and its distribution play an important role in the properties and applications of materials. Thus, it is important to synthesize particles with the desired size and a narrow distribution in an easily-to-control condition. In order to obtain particles with desired size, a variety of methods including hydrothermal method, colloid chemistry method, solid state method and so on [13–17], have been developed for the chemical preparation of relatively monodispersed nanoparticles of various semiconductor materials. Although considerable progress has been made in the controlled synthesis of II–VI semiconductor crystallites, the control of the size and shape of particles still be the main problem in preparation of these materials. In this paper, the extractant (primary amine N1923) was used to control the size of ZnS and a new method to prepare materials, extractionsolvothermal, is proposed. The primary amine N1923 (R1R2CHNH2) was purified as described in literature [18]. The other chemicals were of analytical grade. The procedure to prepare ZnS is as follows: The negative ions of zinc, for example ZnCl2− 4 , were formed by adding NaCl into the ZnCl2 solution in which the pH value is 3; and zinc ions were extracted into organic phase by primary amine N1923 which is pretreated according to the different experimental conditions; then the organic phase was transferred into the Teflon lined stainless autoclave; after the absolute ethanol and CS2 were added into the autoclave, the autoclave was heated at 180 ◦C for 18 h.