Abstract: In a slide bearing assembly 12 comprising a shaft 22 and a bushing 16 which is made of a porous sintered material having a large number of pores 25, the bushing 16 is impregnated with a lubricant 24 containing 2.0 to 30 wt % of solid lubricating fine particles 26 made of at least one selected from among MoS2, WS2, and hexagonal BN, and the shaft 22 and the bushing 16 are used at surface pressure not lower than 6 Kgf/mm2 and sliding speed in the range of 2 to 5 cm/sec. This realizes prolongation of a period during which sliding operation can be continued in an oilless self-lubricating state even under a situation of sliding at a very low speed or angular motion in a very small stroke.