A series of poly(trimethylenecarbonate-epsilon-caprolactone)-block-poly(p-dioxanone) copolymers were prepared with varying feed rations by using two step polymerization reactions. Poly(trimethylenecarbonate)(epsilon-caprolactone) random copolymer was synthesized with stannous-2-ethylhexanoate and followed by adding p-dioxanone monomer as the other block. The ring opening polymerization was carried out at high temperature and long reaction time to get high molecular weight polymers. The monofilament fibers were obtained using conventional melting spun methods. The copolymers were identified by H-1 and C-13 NMR spectroscopy and gel permeation chromatography (GPC). The physicochemical properties, such as viscosity, molecular weight, melting point, glass transition temperature, and crystallinity, were studied. The hydrolytic degradation of copolymers was studied in a phosphate buffer solution, pH = 7.2, 37 degrees C, and a biological absorbable test was performed in rats. (c) 2005 Wiley Periodicals, Inc.