In this research, we study the effect of synthesis method on properties of YBCO superconductors, and explore the effects of Mn, Cr and Li substituions on the system. Y1-xMxBa2Cu3O7 ?? _ (M = Co, Fe, Cr, Mn, Li) high- T c superconductors with different doping levels of x = 0, 0.004, 0.01 and 0.02 were prepared by sol-gel method. In order to obtain an optimal sol-gel method for the first time in our group, and to compare the results with already synthesized solidstate samples, a pure sample along with previous dopings of Co and Fe were prepared. The obtained samples were examined by an AC susceptometer. The magnetic susceptibility of both synthesis methods showed nearly identical profiles which shows the same transition temperature for both methods. The optimal sol-gel preparation method was used to study Mn, Li and Cr substitutions for Y site. In the quantum BCS theory, phonon mediated electron pairing is introduced where ”magnetism” opposes supercoductivity. Considering these two ideas, Li (with a high phonon frequency), Mn and Cr (magnetic ions) were selected as doping elements. Magnetic susceptibility, critical current density, XRD and SEM data were collected for the samples. XRD results indicate that all samples are single phased and are formed in orthorhombic 123 crystal structure. Also, the samples showed very high critical current density (Jc) values compared to solid-state samples which means the J c values are highly dependent on the synthesis method. AC magnetic susceptibility measurments showed slightly decreased transition temperatures in Mn, Li and Cr doped samples. Critical density values are highly dependent on the synthesis method. In brief we believe these result are the first observation of which cuprate superconductors follow and obey the spin fluctuation model for pairtin.