A seatbelt apparatus includes an electric motor 20 for winding a seatbelt 12, and a microcomputer 30 for controlling the electric motor 20. The microcomputer 30 controls the electric motor 20 so as to wind the seatbelt 12 at a winding load which increases to a first winding load at a first rising gradient when collision is detected using a detected length and a detected vehicle velocity by a length sensor 41 and a vehicle velocity sensor 42. The microcomputer 30 controls the electric motor 20 so as to wind the seatbelt 12 at a winding load which increases to a second winding load which is larger than the first winding load at a second rising gradient which is larger than the first rising gradient when an emergency braking operation is detected by detection signal from a brake switch 43. Therefore, the seatbelt can be wound at a winding mode and a winding load which can protect a passenger without giving much feeling of discomfort.