The introduction of MPLS into Internet makes the Internet traffic engineering possible.It is important to balance the traffic load among several parallel explicit LSPs so as to avoid congestion and optimize the network capacity.The total traffic delay is the most valuable and practicable optimization object for traffic engineering.By analysing the constraint relationship between average packet delay and traffic load

the existence of optimum solution is proved and its mathematical result is gotten.Anovel adaptive traffic contribution method based on such optimization object is proposed in the paper.Both theoretical analyses and simulation bear out the merits of simpleness.speediness and convergence.