The behavior of some biopolymeric metal-alginate hydrogel spheres of ionotropic nature in aqueous solutions has been investigated. Cross-linked ionotropic biopolymeric hydrogels such as MnII , CoII , NiII , CaII, SrII and SeIV-alginate showed an appreciable tendency for swelling in water, whereas that of CuII-, SnII-, BaII, PbII, AlIII, CrIII and FeIII-alginates showed a remarkable tendency for shrinking. The swelling processes were accompanied by an increase in volume and transparency; while a decrease in the pore size with a simultaneous increase in hardness was followed the shrinking processes. Drying of these metal-alginate ionotropic hydrogel spheres indicated that the water content exceeds 90% of the gel weights. The kinetics of swelling and shrinking processes have been studied. The factors which affect that behavior were examined and discussed in terms of the mechanical stability and the changes in some rheological properties of these ionotropic hydrogel spheres.