Magnetic clouds, as subsets of Interplanetary Coronal Mass Ejections, are modulating the interplanetary space. We present six observed magnetic clouds and simulate them according to the circular and the new elliptic cylindrical models. Both models apply to magnetic clouds attached to the sun and the simulations estimate the characteristics of the clouds, such as probable shapes, orientation of their axis, duration, etc. In general, magnetic clouds can be described by closed (attached) cylindrical models, but in cases of constant solar wind speed the elliptic cloud fits better observations than the circular one. (This presentation is supported by the Greek-Czech Bilateral Cooperation).