With more and more manufacturers and tradesmen put logistic outsourcing as a viable option for their business, fourth party logistics (4PL) has become a hot topic currently. The concept and the evaluation of 4PL are introduced. Focusing on the e-business environment, the character, the operation mode and the support relation are analyzed. Then, based on a logistic enterprise, structure and functionality of 4PL with reference to the TY-4PL software platform are discussed, critical success factors for realization project are named.