Thin films of ternary REBa 2Cu 3O y (RE=Y 0.33R 0.33Nd 0.33, R=Ho, Gd, and Eu) were grown by pulsed laser deposition technique. The films showed an onset of Tc around 90 K and a sharp transition with a width of ∼1.5 K. Microstructural investigations using AFM revealed that the morphology of the grain growth is mainly controlled by step growth mechanism. The individual grains are observed to merge to form elongated grains. X-ray diffraction pattern showed the grains to be oriented along c-axis. Magnetisation measurements using SQUID magnetometer displayed highest Jc, 3.5×10 7 A/cm 2 at 77 K, 0 T field in (Y 0.33Ho 0.33Nd 0.33)Ba 2Cu 3O y films, where the difference in ionic radii between the RE atoms is maximum.