Although it is preferred to solve the problems and equations accurate and analytical, but with due attention to ever increasing developments of technology, we confront a vast domain of applicable problems in industry that usually using the analytical methods are not available or conducing to very complicated and long solutions. In this situation, applying numerical and approximate will be an appropriate solution for this problem. One of the most accurate and applicable of these methods is finite element. Finite element method like other methods has some problems in which to fulfill these problems the concept of isogeometric analysis is considered. This method solves the complicated geometric problems by using the NURBS functions with an acceptable accuracy and possesses higher speed. Plate analysis is one of the issues, which is outstanding in various engineering industry. At the beginning in plate analysis, justify; LINE-HEIGHT: normal; MARGIN: 0in 0in 10pt" Still is one of the all-purpose materials in industry. Still because of its high strength, comparing to its weight is an appropriate material for the different facilities and industries. In spite of the previously mentioned benefits, in hard environmental conditions like high temperature, its strength decreases highly. That is why composite plates are made. In these plates beside the still plate's specifications, the weakness points are eliminated. Functionally graded material plates are one of the several composites utilizes a lot in industries. In this study using the isogeometric analysis method and NURBS functions, rectangular FGM plates and circular FGM plates in thickness with different boundary condition are assessed. In addition to analyze thicker plates, Reddy third order shear deformation theory is used. Keywords: Isogeometric analysis, NURBS functions, third order shear deformation theory, FGM plates
