Our paper aims to model the yield curve that corresponds to a graphical representation of the yields offered by the bonds of the same issuer according to their maturity, from the shortest to the longest expiration date in the Tunisian bond market (TBM). To get to our objective, we will compare the Nelson-Siegel modeling strategy, which is most often used for the analysis and the hedging of the interest rate risk of portfolios with known flows in practice, to the Svensson modeling strategy, which is the extension of the Nelson-Siegel model. Our sampling data statistically support the evidence that the more appropriate yield curve for the TBM is that estimated by the NelsonSiegel model.