A uniaxial tensile test was performed for polycarbonate (PC)/high-density polyethylene (HDPE)/ethylene-vinyl acetate copolymer (EVA) blends with a fixed EVA content but various PC contents. The double-yielding phenomenon and its composition dependence, as observed in the PC/HDPE blend, were again detected. EVA did not serve as a successful compatibilizer of PC and HDPE in the PC/HDPE/EVA blend. The incorporation of EVA resulted in a larger size and a more irregular shape of the PC fibers, as indicated in the scanning electron microscope observations; this, consequently, produced a higher serious stress concentration in the blend. This more complicated and instable morphology produced different double-yielding behaviors in the PC/HDPE/EVA blends compared with the binary one. (c) 2007 Wiley Periodicals, Inc.