Wurtz coupling of dibutylaminotrimethyl-1,2-dichlorodisilane 1, which is readily available from by-products in the industrially operated direct synthesis of chloromethylsilanes, afforded polymer 2, a partially networked (branched) structure, where the degree of cross-linking depends on the polymerization conditions such as the temperature. Polymer 2, which has a network structure, shows an absorption maximum at about 360 nm that is approximately 30 nm red-shifted relative to the absorption maximum of poly(dialkylsilane)s. In the emission spectra, 2 exhibits a broad emission at 440 and 400 nm, which is ascribed to the network (or branching) silicon units and the linear silicon chains, respectively. The unusual photophysical properties presumably arise from the amino groups on silicon as well as the network structure.