Piezoelectric elastomers were prepared from suspensions of bariumtitanate (BaTiO 3 ) particles in a telechelic polydimethylsiloxane (t-PDMS) by crosslinking the t-PDMS under an electric field. Crosslinking reaction was monitored by measurement of complex dielectric constant ะ ฯช iะ. Dielectric constant ะ increased with increasing BaTiO 3 content, and agreed approximately with the theoretical ะ calculated with the Maxwell-Wagner theory. Piezoelectric constant d 33 of the poled elastomers was measured by application of compressions in the direction of the poling field. It was found that d 33 was of the order of 10 ฯช11 C/N and increased steeply with increasing content of BaTiO 3 but became almost independent of composition in the range of BaTiO 3 content from 3 to 14 vol %. To examine the effect of electric field on the aggregation structure of the particles, we observed light scattering of the suspension under an electric field, and found that the scattering pattern became anisotropic. This indicated that the particles are connected like a pearl necklace and are stretched in the direction of the poling field. The dependence of d 33 on the volume fraction of BaTiO 3 was explained by a model proposed by Banno.