A vehicle power transmission system comprising: a transmission including a plurality of gear stages having gear ratios different from each other, the transmission being configured to transmit a driving force of an engine mounted in a vehicle to a drive wheel of the vehicle while changing the driving force by a selected gear stage; a shift actuator for shifting the selected gear stage in the transmission; a clutch for transmitting or shutting off the driving force transmitted from the engine to or from the transmission; a clutch actuator for mutually switching between the transmitting and the shutting off of the driving force at the clutch; a travelling state detection sensor (150, 151) for detecting whether the vehicle is in a travelling state or in a stopping state; a CA abnormality detection sensor for detecting whether the clutch actuator is normal or abnormal; a shift position sensor for detecting the selected gear stage in the transmission; and a control device for controlling operation of the shift actuator and the clutch actuator, characterized it that the control device is configured to, when having detected that the vehicle is in the travelling state and that the clutch actuator is abnormal by use of the travelling state detection sensor (150, 151) and the CA abnormality detection sensor, - determine whether or not the operation of shifting into a gear stage having a lower gear ratio than the currently selected gear stage in the transmission is permitted, and, if permitted, shifting the selected gear stage in the transmission into a gear stage having a lower gear ratio, and - to control the operation of the shift actuator and cause the selected gear stage in the transmission to be shifted into neutral before the vehicle comes to a stop. a transmission including a plurality of gear stages having gear ratios different from each other, the transmission being configured to transmit a driving force of an engine mounted in a vehicle to a drive wheel of the vehicle while changing the driving force by a selected gear stage; a shift actuator for shifting the selected gear stage in the transmission; a clutch for transmitting or shutting off the driving force transmitted from the engine to or from the transmission; a clutch actuator for mutually switching between the transmitting and the shutting off of the driving force at the clutch; a travelling state detection sensor (150, 151) for detecting whether the vehicle is in a travelling state or in a stopping state; a CA abnormality detection sensor for detecting whether the clutch actuator is normal or abnormal; a shift position sensor for detecting the selected gear stage in the transmission; and a control device for controlling operation of the shift actuator and the clutch actuator, characterized it that the control device is configured to, when having detected that the vehicle is in the travelling state and that the clutch actuator is abnormal by use of the travelling state detection sensor (150, 151) and the CA abnormality detection sensor, - determine whether or not the operation of shifting into a gear stage having a lower gear ratio than the currently selected gear stage in the transmission is permitted, and, if permitted, shifting the selected gear stage in the transmission into a gear stage having a lower gear ratio, and - to control the operation of the shift actuator and cause the selected gear stage in the transmission to be shifted into neutral before the vehicle comes to a stop. - determine whether or not the operation of shifting into a gear stage having a lower gear ratio than the currently selected gear stage in the transmission is permitted, and, if permitted, shifting the selected gear stage in the transmission into a gear stage having a lower gear ratio, and - to control the operation of the shift actuator and cause the selected gear stage in the transmission to be shifted into neutral before the vehicle comes to a stop.