The purpose of this research is to investigate the mechanical property and ductile-brittle transition temperature of Ti-Nb-P added extra low carbon interstitial free steel having a tensile strength of 440 MPa. The mechanical property and transition temperature of hot rolled steel sheets were more influenced by the coiling temperature rather than by the small amount of alloying element. Further, at the same composition, the property of the specimen coiled at low temperature was superior to that obtained at higher coiling temperature. The fracture surface of 0.005C-0.2Si-1.43Mn steel coiled at $630^{circ}C$ showed a ductile fracture mode at $-100^{circ}C$, but coiling at $670^{circ}C$ showed a transgranular brittle fracture mode at $-90^{circ}C$. The galvannealed 0.006C-0.07Si-1.33Mn steel sheet annealed at $810^{circ}C$ has tensile strength and elongation of 442.8 MPa and $36.6\%$, respectively. The transition temperature of galvannealed 0.006C-0.07Si-1.33Mn steel sheet was increased with a drawing ratio, and the transition temperature of the galvannealed 0.006C-0.07Si-1.33Mn steel was $-60^{circ}C$ at a drawing ratio of 1.8