We report the synthesis and characterization of a novel series of main-chain boron-containing conjugated polymers (CPs), boron "doped" polyacetylenes (BPAs), which represent the first examples of main-chain boron-containing CPs without aromatic moieties within the polymer backbone, potentially enhancing electronic delocalization along the main-chain. These polymers are characterized by NMR, absorption and emission spectroscopy, cyclic voltammetry, theoretical calculation, and fluoride titration experiments, providing detailed understanding of the effects from different cross-conjugated side-chains on the physical and electronic properties of this new class of boron-containing polymers.