Three polycarbonate (PC) composites that were reinforced, respectively, with liquid crystalline polymer (LCP), glass fibers, and both of them were prepared by a single injection-molding process. The role of LCP in improving the processibility of the composites was characterized by torque measurement test. The transitions of LCP morphology in two-and three-component composites were investigated by using polarizing optical microscopy and scanning electron microscopy. The micrographs showed a skin-core gradient structure in all three systems investigated, and the addition of glass fiber to the PC/LCP blend affected the morphological transition and content distribution of dispersed LCP phase through the thickness of the injection-molded samples. These results were correlated well with the measurements of tensile mechanical properties and dynamic mechanical analysis. How to fully use the dispersed LCP phase in PC in situ hybrid composites was discussed for the thickness change of core layer and the heterogeneous distribution of more LCP in the core. (C) 2004 Wiley Periodicals, Inc.