This article analyzes the mechanisms of TCP Reno and TCP Veno algorithm with its existing problems, the reasons of packet transmission loss cannot be distinguished accurately, and we propose a comparison of TCP Reno with Veno in order to distinguish the cause of the transmission loss more accurately, and achieve higher network resources utilization .In order to control the congestion and to reduce the packet loss we use Veno algorithm and to achieve high throughput and user friendliness even in the case of high packet loss. INTRODUCTION: