With the step-growth polymerization of bis(oligopeptides) and diisocyanates, two silk-proteinlike multiblock polymers (P1, P2), containing -(Ala)(4)- and -(GlyAlaGlyAla)- sequence derived from the crystalline region of spider dragline silk and silkworm (Bombyx Mori) silk respectively, has been synthesized successfully. The intrinsic viscosities of P1 and P2 measured in dichloroacetic acid at 25 degreesC were 0.31 and 0.26 dL/g. FT-IR, C-13 CP/MAS NMR and WAXD measurements revealed the oligopeptide segments in these multiblock polymers could aggregate spontaneously into beta-sheet structure in solid state. In addition, it was also found there were non-beta-sheet structures in the synthetic polymers, which indicated such polymers had a solid-state structure similar to that of natural silks.