In order to explore the effects of Al2O3 additions at x=0.00, 0.10, 0.20, 0.50, 1.50, and 3.50 wt. %, YBa2Cu3O (YBCO) was synthesized. X-Ray Diffraction and the Thermo Gravimetric Analyzer (TGA) were used to examine the samples (XRD). All samples were created using the solid state reaction procedure, which included calcination at 900°C and sintering at 950°C. According to the TGA study, weight loss was finished at 910°C. Orthorhombic structure with lattice parameters of a=3.821, b=3.880, and c=11.663 was revealed by XRD patterns. The samples with Al2O3 added did not exhibit any new peaks. however, the peaks' sharpness and breadth were altered. The width of the chosen peak and half maximum were used to compute the sizes of the crystallites in the samples. By gradually increasing the amount of Al2O3, the size is raised. Our findings showed that although addition has no impact on the structure, growing crystallite sizes have an impact on morphological pictures.