Abstract: With different additions of hexadecyltrimethylammonium bromide(CTMAB), N-vinyl pyrrolidone(PVP) and their mixture as dispersant, with water, deionized water and embrane-treated water as disperse medium, different TiN nanofluids were prepared under conditions of different ultrasonic dispersion time respectively. And then the copper corrosion behavior in the TiN nanofluid was studied. The results show that the copper corrosion was accelerated with CTMAB as dispersant. The copper corrosion rate increased with the increase of with CTMAB content, and first decreased rapidly with the elongation of ultrasonic dispersion time then changed little over 8 min. The optimum ultrasonic dispersion time was 8 min. the copper corrosion was inhibited with PVP dispersant. The copper corrosion rate decreased with the increase of PVP content, and first increased then decreased with the elongation of ultrasonic dispersion time. The optimum ultrasonic dispersion time was 6-8 min. With water as disperse medium, the copper corrosion rate was the largest, followed by the disperse medium of deionized water, and that with embrane-treated water as disperse medium was minimum.