For exploring the possibility of a hybrid mode with smooth transition from fluid to boundary even to solid lubrication at the elevated temperature, i.e., searching a substance which should be the solid lubricant and oil additive with environmentally friendly characters, a series of perrhenates (the soft double oxide) were synthesized as the candidates because of their crystalline and decomposed products with a good anti–friction behavior, such as Re₂O₇ which might provide the lubrication during oil decomposition for its good sublimation at about 300 ℃. This investigation might be advantage of lubrication for rubbing parts of internal combustion or turbo engine such as piston ring and cylinder liner or exchanger, which were always operated in a cyclical variation of temperature (even to 800 ℃). In this paper, the properties of perrhenates of Fe, Co, Ni, Cu, Pb, Ca, Ba and La synthesized by aqua–solution method were described and their crystalline structures, compositions and morphologies were determined by XRD, SEM–EDS. For understanding their lubricating behaviors in both dry sliding and base oil pentaerythritol ester (PETE), their frictional behaviors between Si₃N₄ ball and superalloy disc were tested in pin-on-disc on universal micro–tribotester (UMT–2) from 20 to 750℃. The results show that most synthesized perrhenates are crystal powder except the synthesized gel–like ferric perrhenate, their crystalline structures are coincidence with powder diffraction file (PDF) cards, and compositions are very close to the stoichiometic values. Some of the synthesized perrhenates exhibit certain lubrication at 300—750 ℃, in both dry sliding and oil lubrication with addition of the synthesized perrhenate whch were verified in eciprocating sliding. The variation of friction coefficients with temperature probably results from the formation or removal of soft oxides at high temperature. The good anti–frictional behaviors of the synthesized perrhenates of Ca, Co and Cu in a wide temperature range seem to imply them to be developed as the candidates of additive in a hybrid lubricating mode for the engine operating in cyclical variation of temperature.