A vehicle drive system includes a slip acquisition unit that acquires that an excessive slip of front wheels or rear wheels has occurred, an addition slip point calculating unit that calculates addition slip points in a time-discrete manner, based on the slip acquisition unit having acquired that the excessive slip has occurred, a cumulative slip point calculating unit that accumulates the addition slip points and calculates a cumulative slip point over time, a drive state switching unit that, switches between 2WD and AWD based on cumulative slip points, and an increase forbidding determination unit that forbids addition or accumulation of the addition slip points, or increase of the cumulative slip points, in a case where a lateral acceleration correlation value that has correlation with lateral acceleration of the vehicle exceeds a lateral acceleration threshold value.