A start control system for a vehicle, comprising: an input unit that inputs an accelerator position; a clutch controller that controls a clutch; and a storing unit (53 or 54) that stores setting information, said storing unit (53 or 54) comprising a setting value storage that stores a first setting value used to control said clutch to attain a start standby state and a second setting value used to control said clutch to attain a start preparation state, and an association information storage that stores association information that associates said accelerator position with an engine target speed, said clutch controller comprising, a first controller that controls said clutch to attain said start standby state based on said first setting value upon determining that said vehicle has proceeded to a start standby period, a second controller that controls said clutch to attain said start preparation state based on said second setting value upon determining that said vehicle has proceeded to a start preparation period, a distance between clutch disks (3b, 3c) in said start preparation state being smaller than that in said start standby state, and a third controller that controls said clutch in such a direction that the distance between the clutch disks (3b, 3c) is smaller than that in said start preparation state and carries out such control that an engine speed approaches said engine target speed based on said association information, characterized in that the start control system further comprising: a speed detector that detects a speed of said vehicle, wherein said second controller comprises a determining unit that determines that a start shock has occurred if a speed detected by said speed detector includes a first rise period, a drop period subsequent to said first rise period, and a second rise period subsequent to said drop period within a prescribed time period after controlling said clutch to attain said start preparation state, and a first updating unit that updates said second setting value so that the distance between the clutch disks (3b, 3c) increases when said start shock has occurred before start of control by said third controller or a second updating unit that updates said second setting value so that the distance between the clutch disks (3b, 3c) is reduced when said start shock has occurred after start of control by said third controller. an input unit that inputs an accelerator position; a clutch controller that controls a clutch; and a storing unit (53 or 54) that stores setting information, said storing unit (53 or 54) comprising a setting value storage that stores a first setting value used to control said clutch to attain a start standby state and a second setting value used to control said clutch to attain a start preparation state, and an association information storage that stores association information that associates said accelerator position with an engine target speed, said clutch controller comprising, a first controller that controls said clutch to attain said start standby state based on said first setting value upon determining that said vehicle has proceeded to a start standby period, a second controller that controls said clutch to attain said start preparation state based on said second setting value upon determining that said vehicle has proceeded to a start preparation period, a distance between clutch disks (3b, 3c) in said start preparation state being smaller than that in said start standby state, and a third controller that controls said clutch in such a direction that the distance between the clutch disks (3b, 3c) is smaller than that in said start preparation state and carries out such control that an engine speed approaches said engine target speed based on said association information, characterized in that the start control system further comprising: a speed detector that detects a speed of said vehicle, wherein said second controller comprises a determining unit that determines that a start shock has occurred if a speed detected by said speed detector includes a first rise period, a drop period subsequent to said first rise period, and a second rise period subsequent to said drop period within a prescribed time period after controlling said clutch to attain said start preparation state, and a first updating unit that updates said second setting value so that the distance between the clutch disks (3b, 3c) increases when said start shock has occurred before start of control by said third controller or a second updating unit that updates said second setting value so that the distance between the clutch disks (3b, 3c) is reduced when said start shock has occurred after start of control by said third controller.