Both short range attraction and long range electrostatic repulsion exist among globular protein Bovine Serum Albumin in solution below its iso electric point (pI ≈ 4.8). At pD ≈ 4.0, below pI, protein has a net positive surface charge although local charge in homogeneity presents. Small angle neutron scattering study reveals that in the presence of both mono-(Na⁺) and di-(Ni²⁺) valent ions attractive interaction increases and repulsive interaction decreases with the increase of salt concentration. However, for tri-valent (Fe³+) ions, both attractive and repulsive interaction increases with increasing salt concentration but the relative strength of repulsion is more than the attraction.