A CdS1-xSex red pigment with spherical particles is urgently needed for red ceramic ink preparation to enrich the available ink types and enhance the decoration effect of ceramic tiles, in this study, spherical CdS0.75Se0.25 red pigment was synthesized through a facile two-step in situ reaction and the sphere formation mechanism was elucidated in detail. The CIE L*a*b* parameters of synthesized CdS0.75Se0.25 were as follows: L* = 47.76, a* = 43.91, b* = 30.05, implying a bright red color. As the first step, CdS spheres were prepared through a process of gradual random attachment and surface-induced nucleation; as the second step, CdS1-xSex spheres were synthesized through an in situ reaction based on the previously prepared CdS spheres. The spherical "core", CTAB template and controlled reaction speed are crucial to the spherical morphology of the CdS(1-x)Se(x )formations. Spherical CdS(1-x)Se(x )exhibited a considerable red-shift compared with spherical CdS as a result of the partial substitution of Se2- ions for S2- ions. The synthesized spherical CdS0.75Se0.25 red pigment had a mean particle size of about 448 nm, which is consistent with the requirements for ceramic ink preparation. Hence, it is a promising candidate for further study regarding their potential use as ceramic ink in ink-jet printing. (C) 2017 Elsevier B.V. All rights reserved.