The stabilized nylon-6 adding stabilizer and nylon-6 without stabilizer were prepared by melt blending. The variation of crystallization behavior and properties of stabilized nylon-6 and nylon-6 with different aging time at 160 ℃ were investigated by DSC, XRD, DMA and FT-IR. The results indicate that during thermal oxidative aging, the crystallization temperature, crystallinity and mechanical properties of nylon-6 increase and then decrease, impact toughness decreases and storage modulus increases. The crystallization temperature, crystallinity and retention of mechanical properties of nylon-6 are improved after the addition of the stabilizer, but the glass transition temperature change a little. The crystalline phase of stabilized nylon-6 and nylon-6 was mainly α phase and γ phase respectively after aging for 36h.