Pure TiO2 thin films and Al doped TiO2 thin films have been prepared by spin coating method. This work is carried out to determine the effect of Al on TiO2 thin film. Because of Al doping thickness, optical properties, band gap, surface morphology, and structural properties of TiO2 thin film changes. X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Gravimetric Analysis, and UV-vis. Spectroscopy were carried out to find out the micro-structure, surface morphology, surface roughness, thickness and optical properties of the thin films. 0.5 M TiO2 thin film shows 473 nm thicknesses where it changes with Al doping. Al also changes the crystal structure and the surface roughness of the film and both of them are carried out by using XRD analysis and AFM analysis. The surface roughness of the films was 12.239 nm for undoped TiO2 thin film and for 6% Al doped the roughness increases to 85 nm which were calculated by using AFM analysis. The grain size of Al doped TiO2 thin film was 19.51 nm and 26.95 nm were measured by XRD analysis.