Three new linear C-14 polyyne (= polyacetylene) glucosides, cordifolioidynes A-C (1-3), together with two known polyynes, lobetyol (4) and lobetyolin (5), and five known phenylpropanoids, i.e., sinapinaldehyde (6), coniferaldehyde (7), coniferoside (8), sachaliside (9), and isoconiferin (10), were isolated from the roots of Codonopsis cordifolioidea. The structures of 1-3 were established from spectral evidences and by characterization of their hydrolysis products. Acid hydrolysis of I afforded the aglycone la, while hydrolysis of 2 and 3 gave the cyclization products 2a and 3a, respectively. Compounds 4-10 were isolated from this plant for the first time. The antibacterial activity of compounds 1-5 were assessed against eight microbial strains by the agar dilution method, none of them exhibited antibacterial effects at concentrations up to 100 mu g/ml.