A sliding bearing assembly for joints of construction equipment can be provided, in which production cost is reduced by decreasing the used amount of Cu and sulfides having high fixability to a matrix are dispersed. The sliding bearing assembly for joints of construction equipment, includes at least a shaft and a bush made of an iron-based sintered material which functions as a sliding bearing, in which the bush has the overall composition of, by mass %, 0.1 to 10% of Cu, 0.2 to 1.2% of C, 0.03 to 0.9% of Mn, 0.36 to 1.68% of S, and the balance of Fe and inevitable impurities, a metal structure has pores dispersed in a matrix mainly including a martensite structure and sulfide particles precipitated and dispersed, and the sulfide particles are dispersed at 1 to 7 volume % in the matrix.