en Continuous Optimization Continuous Optimization پژوهشی Original The conjugate gradient method (CGM) stands out as one of the most rapidly growing and effective approaches for addressing unconstrained optimization problems. In recent years, significant efforts have been dedicated to adapting the CGM for tackling nonlinear optimization challenges. This research article introduces a new modification of the Fletcher&ndash;Reeves (FR) conjugate gradient projection method. The proposed method is characterized by its sufficient descent property, and its global convergence has been established under specific assumptions. Numerical experiments conducted on a range of functions from the CUTEr collection demonstrate the potential and effectiveness of the proposed methods.<br> &nbsp; Nonlinear optimization, line search, spectral conjugate gradient method, suffcient descent property. 63 75 http://iors.ir/journal/browse.php?a_code=A-10-6097-1&slc_lang=en&sid=1 Mariya Toofan Mariyatoofan74@gmail.com 00031947532846003047 00031947532846003047 Yes Department of Applied Mathematics, University of Mazandaran, Babolsar, Iran Gohar Shakouri gshakoori2@gmail.com 00031947532846003048 00031947532846003048 No Department of Basic Sciences, Rahman Institute of Higher Education, Ramsar, Iran