Tissue engineered pulmonary valve (TEPV) has been suggested as a potential approach for replacement congenitally defective pediatric heart valves. As with all heart valves, the leaflet shape during systole and diastole is essential to the normal function of PV. In this work, we present a design framework on optimal unloaded shape of TEPV leaflet for single leaflet replacement surgery by incorporating key experimental data within a finite element (FE) simulation framework. The mechanical properties of the material for leaflet replacement are measured by biaxial tensile and flexural deformation modes. The scaffold construct is modeled as a transversely isotropic hyperelastic material using a generalized Fung-type constitutive model. The quasi-static deformation of leaflet from open to close is simulated by finite element method using explicit time integration. The optimal shape of leaflet is determined by minimizing the surface distance between the deformed leaflet shapes obtained from FE simulation of TEPV and the native ovine PV shape as obtained from microCT imaging. This study aims to provide an approach toward designing the shape of leaflet for PV replacement surgery.