Abstract: Considering the ubiquitous uncertainty associated with logistics operations, we investigate a fourth party logistics routing problem (4PLRP) with a time window in uncertain environments. Under the constraint of total transportation cost, we establish a 4PLRP chance model with a time window and stochastic transportation time (UCM) to maximize the chances that the total transportation time will satisfy the time window. Then, to improve solving efficiency, we transform the chance model into a clear equivalent deterministic model, and use an ant colony algorithm to solve the deterministic model. Our numerical analysis results verify the effectiveness of the proposed model and algorithms.