Ultrahigh molecular weight polyethylene (UHMWPE) fiber/carbon fiber hybrid composites were prepared by inner-laminar and interlaminar hybrid way. The mechanical properties, dynamic mechanical analysis (DMA), and morphologies of the composites were investigated and compared with each other. The results show that the hybrid way was the major factor to affect mechanical and thermal properties of hybrid composites. The resultant properties of inner-laminar hybrid composite were better than that of interlaminar hybrid composite. The bending strength, compressive strength, and interlaminar shear strength of hybrid composites increased with an increase in carbon fiber con-tent. The impact strength of inner-laminar hybrid composite was the largest (423.3 kJ/m(2)) for the UHMWPE fiber content at 43 wt % to carbon fiber. The results show that the storage modulus (E'), dissipation factor (tan delta), and loss modulus (E") of the inner-laminar hybrid composite shift toward high temperature remarkably. The results also indicate that the high-performance composite with high strength and heat resistance may be prepared by fibers' hybrid. (c) 2006 Wiley Periodicals, Inc.