Network bandwidth has been exponentially enhanced in the last few years, and as a result the availability of networks offering high transmission capacity with low error rates has been risen as well. Consequently, many existing protocols become quickly obsolete for this new environment. In this thesis, we propose a new flow control method of transport layer for high speed networks. The new flow control algorithm minimizes processing overhead to recover from errors, and it also reduces acknowledged messages between a sender and a receiver by using an efficient buffer management scheme. The performance improvement is measured by a simulation model which is driven by real network traces.