Abstract: The tribological properties of Ti3SiC2 pin sliding against a self-lubricating composite PM304 disk at ambient temperature up to 630?C were investigated. Comparison was made on the tribological properties of Ti3SiC2/PM304 and Ni-Cr alloy/PM304 tribo-pairs. The findings indicated that Ti3SiC2/PM304 tribo-pair exhibited better tribological property than that of Ni-Cr alloy/PM304 tribo-pair at elevated temperatures. Ti3SiC2/PM304 tribo-pairs showed excellent tribological properties from 400?C to 630?C. Mechanical mixed layers on the worn surfaces of both PM304 and Ti3SiC2 were found at room temperature to 300?C as a result of pullout of Ti3SiC2 grains and transference of PM304. At 400?C to 600?C, mechanical mixing was greatly inhibited. Lubricious transfer layer, which was Ag-rich, was corresponding to the good tribological behavior of the Ti3SiC2/PM304 tribo-pair. And the integrity of the lubricious transfer layer has pronounced influence on the friction and wear of Ti3SiC2/PM304 tribo-pair.