Monodispersed peanut-shaped mesoporous SrSO4 (celestine) particles were synthesized via a simple precipitation reaction of SrSO4 from poly-(styrene-alt-maleic acid) (PSMA) aqueous solution at ambient temperature. The as prepared products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen absorption-desorption measurement. The results show that the as-obtained SrSO4 particles in the presence of 2 g L-1 PSMA appear monodisperse and peanut-shaped. The average length and aspect ratio of the particles are about 1.5 mu m and 2, respectively. The as-prepared SrSO4 particles have a relatively large Brunauer-Emmett-Teller (BET) surface area of about 72.7 m(2) g(-1) and a mesoporous structure with an average pore size of about 2.9 nm. A preliminary understanding, involving a three-stage evolution mechanism, has been proposed to account for the formation process of the as-obtained monodispersed peanut-shaped mesoporous celestine particles. (c) 2005 Elsevier B.V. All rights reserved.