This is a comparative study where the seismic response of aground supported liquid storage tank is analyzed incorporating four different isolators belonging to the same category of sliding isolator having variable curvature (SIVC). In recent years, various isolators have been developed with numerous different properties. One of them is curvature, a property by which time-period of structure is highly influenced. Here, a comparative study is executed between four isolators namely Variable curvature friction pendulum isolator of the order 4th (VCFP O4), Variable curvature friction pendulum isolator of the order 6th (VCFP O6), Polynomial defined sliding isolator having variable curvature of the order 3rd (PSIVC-3rd) and Polynomial defined sliding isolator having variable curvature of the order 5th(PSIVC-5th)which have variable curvature influenced by their polynomial functions. The effectiveness of these four passive base isolation systems for vibration control of ground supported liquid storage tank under near-fault ground excitations has been investigated. Newmark’s linear acceleration method is utilized in this study for solving equations governing the motion of the structure. From this comparative study, VCFP O4 is found to be most effective for both slender as well as broad tanks in reducing the seismic response.