A new method of the synthesis of oligo(tetramethylene succinate-co-carbonate) diols using dimethyl succinate, 1,4-butanediol and tetramethylene bis(methyl carbonate) was elaborated. The resultant oligomerols (Mn = 2600- 3700) were characterized by FTIR, 1H NMR, GPC and DSC analysis. Depending on the content of carbonate units in the polymer molecules, the melting point of the crystalline phase changes significantly. The synthesis of poly(ester-carbonate-urea-urethane)s was carried out with two aliphatic diisocyanates - cyclic IPDI or linear HDI. The resultant products exhibited very good mechanical properties - tensile strength up to 60 MPa and elongation at break about 500%. Preliminary studies confirmed that the presence of ester units in the soft segments as well as lack of crystalline phase significantly enhances the biodegradability of the PUR in comparison to that of polyurethanes based on carbonate oligomers.