A blend of biodegradable poly(ε-caprolactone) (PCL) and sustainable poly(propylene carbonate) (PPC) was prepared by melt mixing to obtain an excellent balance of performance. The miscibility, morphology, thermal behavior, mechanical, and rheological properties of PCL/PPC blends were investigated. Dynamic mechanical analysis results revealed PCL and PPC were immiscible. Minor phase-separated morphology was observed from SEM for PCL/PPC blends. The incorporation of PPC accelerated the crystallization rate of PCL, whereas reduced the degree of crystallinity. Significant enhancement of stiffness and strength of PCL was achieved by the introduction of PPC. The Young's modulus and yield strength of blend containing 30 wt% PPC were increased by 65% and 17%, respectively, compared with neat PCL, and the elongation at break was still above 600%. Moreover, the viscosity and elasticity of PCL melt were improved by the presence of PPC. The synergetic improvement in mechanical and rheological properties is important for expanding the application of PCL. [ABSTRACT FROM AUTHOR]