Polycarbonate (PC) can be easily crystallized by injecting a very dilute benzene solution of PC directly into liquid nitrogen, and then freeze-drying to remove the solvent. The crystallinities of these prepared samples were characterized by wide-angle X-ray diffraction (WAXD). The results of WAXD studies showed that there is a concentration boundary in very dilute solution for crystallizability of PC : near the boundary concentration, the solution has a lower chain entanglement level, and as a result, crystallizes more quickly and completely than more highly entangled PC. By annealing these fewer-chain-entanglement samples at 190 degrees C for 289 h, crystallinity reaches a maximum value of 79.6%, which is much higher than that of annealing ordinary or other solution-crystallized samples.