Abstract: The influence factors and regulation of the agglomeration of nano copper powder in ethanol were studyed. The results show that with prolonging the setting time, the agglomerate size of nano copper powder gradually increased, as well as the size range until the balance of agglomeration, then the range of particle size gradually became narrow again. When the agglomeration stroke a balance, the agglomerate size of nano copper powders increasing with increase of mass fraction of nano copper powders got to the limit. And the velocity of agglomeration of nano copper powders in suspension rose when it mass fraction increased.