A Cardiopulmonary (CP) model to study the interaction between Cardiovascular(CV) and Respiratory System (RPS) is presented. It includes detailed anatomical representations of CV, RPS and baroreflex control. The respiratory induced variations on CVS is realised by intrapleural pressure (Ppl). The state equations are solved using 4th order Runge-Kutta method. Sensitivity analysis is performed. The RPS influences on aortic pressure is presented for quiet breathing and Valsalva Manuever and found have good agreement with literature data. Our model can simulate various CP diseases and therefore it can be used to study interactions hemodynamics in normal and pathological conditions. © 2011 Inderscience Enterprises Ltd.