In the future, mobile technologies will be important roles in the communication with the explosive growth of demanding for wireless portable devices. Mobile IP is IETF's solutions to support mobility in Internet. We propose a route optimization scheme, Proxy Home Router-Route Optimization(PHR-RO) in the Mobile IP environment. Our route optimization scheme use a router called Proxy Home Router(PHR) which exists along the path between home agent and correspondent node. It has an ability to manage binding information. Therefore, instead of home agent, PHR close to the correspondent node can intercept and tunnel datagrams destined for the mobile node. In this paper, we describe our PHR-RO architecture, its operations, its messages, message formats, some special mechanisms and our simulation results.