Recently, many successful methods have been developed to achieve analytical solutions of non-linear partial differential equations. In this study, some new exact solutions of the non-linear coupled Klein-Gordon system and non-linear modified Benjamin-Bona-Mahony equation have been obtained by using functional variable method (FVM). Additionally, all solutions have been examined and three dimensional graphics of the obtained solutions have been drawn by using the Mathematica program. These equations have been used in various fields such as plasma physics, biophysics, and fluid dynamics. The main advantage of FVM is generate more solutions than other analytical methods and therefore, FVM is an effective and powerful method to solve evolution equations in engineering and mathematical physics.