There are provided organic acid anion containing aluminum salt hydroxide particles represented by the following general formula (I): M.sub.a[Al.sub.1-xM'.sub.x].sub.bA.sub.zB.sub.y(OH).sub.n.mH.sub.2O (I) (wherein M is at least one cation selected from the group consisting of Na.sup.+, K.sup.+, NH.sup.4+ and H.sub.3O.sup.+, M' is at least one metal cation selected from the group consisting of Cu.sup.2+, Zn.sup.2+, Ni.sup.2+, Sn.sup.4+, Zr.sup.4+, Fe.sup.2+, Fe.sup.3+ and Ti.sup.4+, A is at least one organic acid anion, B is at least one inorganic acid anion, and a, b, m, n, x, y and z satisfy 0.7.ltoreq.a.ltoreq.1.35, 2.7.ltoreq.b.ltoreq.3.3, 0.ltoreq.m.ltoreq.5, 4.ltoreq.n.ltoreq.7, 0.ltoreq.x.ltoreq.0.6, 1.7.ltoreq.y.ltoreq.2.4, and 0.001.ltoreq.z.ltoreq.0.5, respectively.)The particles are in the shape of grains, pairs, rectangular parallelepiped, disks (go stones), hexagonal plates, rice grains or cylinders and have a uniform particle diameter.