The conventional transport protocols, developed on top of the low-bandwidth high-error network services, exhibit poor performances when operating in the new high-bandwidth low-error networks. A new transport protocol HSTP(High Speed Transport Protocol) was proposed to take advantage of the new network environment. This paper gives a performance evaluation by simulation technique of the proposed HSTP and conventional TP4(Transport Protocol class 4) in their data trans-fer characteristics. The performance variation by HSTP and TP4 are investigated when their various error control techniques are employed, three different techniques for HSTP, and two for TP4. The performance enhancement in HSTP is also evaluated when the rate control technique is used as part of the flow control mechanisms.