The effects of bulk processing conditions on the bulk properties of modacrylic fibers were studied. The results showed that the pre-wet sprayed filament was textured more uniformly than the unsprayed one. It also showed that the crimp rigidity increased with increasing gear temperature, but above an optimum temperature it decrease with increasing gear temperature, and the fibers showed apparent damage above the optimum temperature. The important parameters with affect the bulk property are the texturing temperature and its residence time. The optimum gear temperature of modacrylic fiber was about 8$0^{circ}C$ to 9$0^{circ}C$. An increase in the residence time increases the crimp rigidity very sharply, and then it tends to flatten out to constant value at longer residence time.