Abstract: A heat exchanger for cooling electrical elements of a vehicle includes: a pair of coolers disposed over and under an electrical element module, respectively, and each having a plurality of channels longitudinally formed to pass cooling fluid; pipe couplers respectively coupled to first ends of the pair of coolers to pass cooling fluid, having protrusions on first surfaces facing each other, respectively, and connected with pipes on second surfaces; bellows couplers respectively coupled to second ends of the pair of coolers to pass cooling fluid and having protrusions on first surfaces facing each other; and a bellows having top and bottom openings fitted on the protrusions, and being able to contract. According to the heat exchanger for cooling electrical elements of a vehicle, the possibility of leakage of cooling water can be reduced and the gap between the top and the bottom can be adjusted within a larger width.