The catalytic cross-dehydrocoupling polymerization of 1,4-bis(dimethylsilyl)benzene with water, ammonia, disilanol, aliphatic and aromatic diols, and dicarboxylic acids was successfully conducted under mild conditions to afford silphenylene-containing polycarbosilazane, polycarbosiloxanes, poly(silyl ether)s, and poly(silyl ester)s. This efficient novel route allowed accessing various silphenylene-containing polymers with well-defined structures which were verified by NMR, IR, and SEC analyses. The influence of the structures of the constitutional units between silphenylene groups on the transition temperatures, crystallization behavior, thermal stability, solubility, and degradability of these polymers was also systematically investigated.