Abstract: A hardware system designed to support the peer-to-peer Ethernet is presented.Sampled datum transferring on process level in digital substation can be employed in either networking mode or peer-to-peer mode.In networking mode,a stable unified clock source for whole substation is necessary,and the substation always takes risks of clock source and the integrity of the network.When transferring IEC 61850-9-2 data frames in peer-to-peer mode,it will take the benefits of flexible configuration and high compatibility of IEC 61850-9-2,and provides much more reliability for the protection system with fixed data transferring delay.In 500 kV Lanxi substation upgrade project,the peer-to-peer IEC 61850-9-2 sampled value is applied.