A type of anhydrous electrorheological (ER) material of copper phthalocyanine (CuPC)-doped mesoporous TiO2 was synthesized by in situ micelle-assisted incorporation CuPC during mesoporous TiO2 synthesis. TEM, XRD and the nitrogen adsorption-desorption isotherms demonstrated that the material had mesoporous structure and an anatase framework. The ER behavior of the suspensions of CuPC-doped mesoporous TiO2 in silicone oil with the different volume fractions was investigated under an applied electric field. It is found that the suspensions showed visible electrorheological behavior which were compared with that of pure TiO2. The dopants of CuPC molecules within the mesochannel of TiO2 mesoporous sieve improved the conductivity of the particles and produced a proper conductivity of similar to 10(-7) S m(-1). Dielectric spectra of the ER fluid were measured to examine the peak of epsilon" should appear in the frequency range of 10(2)-10(5) Hz and have a large Delta epsilon' in this frequency range. Therefore, the both properties may make a conjunct effect on electrorheological behavior. (c) 2005 Elsevier Inc. All rights reserved.