A nonsingular universe in string cosmology

We consider the low-energy effective string action in four dimensions inclu ding the leading order-alpha' terms. An exact homogeneous solution is obtai ned. It represents a nonsingular expanding cosmological model in which the tensor fields tend to Vanish as t --> infinity. The scale factor a(t) of th e very early universe in this model has the time dependence a(t)(2) = a(0)( 2) + t(2). The violation of the strong energy condition of classical Genera l Relativity to avoid the initial singularity requires that the central cha rge deficit of the theory be larger than a certain value. The significance of this solution is discussed.