In order to improve the optical properties and enhance the stability of Zn1–xCdxS nanoparticles, which are important optoelectrical materials, the ternary Zn1–xCdxS nanoparticles were enclosed in a layered octosilicate by a three-step process, namely (i) protonation of Na-octosilicate, (ii) ion-exchange in order to introduce Zn and Cd ions into the interlayer space, and (iii) addition of S2– to form Zn1–xCdxS particles in the interlayer space of the octosilicate. The basal spacing (∼10 Å) of the final ZnCdS-Oct-n (n = 1, 2, 3, 4) composites noticeably increased in comparison with that of the precursor H-Oct (7.5 Å). This may be attributed to the incorporation of larger size Zn1–xCdxS particles into the interlayer space of H-Oct. The UV-visible spectra of the composites suggested that the transmission band-edges gradually shifted to low energy with increasing molar ratio of Cd/Zn. Moreover, the transmission band-edges of the composites are between those of layered Octosilicate, ZnS, and CdS. TEM observation confirmed that the size of Zn1–xCdxS nanoparticles enclosed in the layered silicate was about ∼3–5 nm.