A new polysiloxane (P2), with a high density of the indole-based chromophore and carbazolyl side groups, was prepared. Thus a polysiloxane (P1), with indole and carbazolyl groups as side chains, was first synthesized through a hydrosilylation reaction, and then the post-azo coupling of p-nitrobenzenediazonium fluoroborate toward the indole ring gave the mulifunctional indole-based chromophore-functionalized polysiloxane (P2). Molecular structural characterization for the polymers was determined by H-1-NMR, IR, and UV-visible spectra, gel permeation chromatography, and differential scanning calorimetry. The polymers were easily soluble in common organic solvents. The poled film of P2 revealed a resonant d(33) value of 27 pm/V by second-harmonic generation measurements. (C) 2004 Wiley Periodicals, Inc.