A method for forming SBT ferroelectric thin film. Sr(C.sub.5 F.sub.6 HO.sub.2).sub.2, Bi(C.sub.6 H.sub.5).sub.3 and Ta(C.sub.2 H.sub.5 O).sub.5 are used as the precursors of Sr, Bi and Ta and bubbled at a temperature of 110-130.degree. C., 140-160.degree. C., and 120-140.degree. C., respectively. The deposition of the precursors on a substrate is carried out at 500-550.degree. C. in plasma by using an RF power of 100-150 W. Having a residual polarity (Pr) of 15 .mu.C/cm.sup.2 or higher and a coercive electric field (Ec) of 50 kV/cm or less and, the SBT ferroelectric thin film does not show a fatigue phenomenon until 1.times.10.sup.11 cycles as measured under 6V bipolar square pulse in the structure comprising Pt upper and lower electrodes and thus, can be applied for non-volatile memory devices.