This study discusses the use of C1 rational cubic spline mterpolant of the form cubic/quadratic with three shape parameters to preserves the monotonicity of the given data sets. The data dependent sufficient conditions for the monotonicity of rational mterpolant are derived on one parameter while the other two parameters can be further utilized to changes and modify the fmal shape of the monotomc interpolating curves. These sufficient conditions will ensure the existence of monotone rational mterpolant. Several numerical results are presented to test the capability of the proposed rational interpolant scheme. Comparisons with the existing scheme also have been done. From all numerical results, the new rational cubic spline interpolant gives satisfactory results. © Medwell Journals, 2014.