In the present Work, effect of substrate temperatures on the optical and morphological properties of In2O3 trioxide thin film has been carried out using Reactive Pulsed Laser as a Deposition technique (RPLD). 1.064µm, 7 nsec Q-switch Nd-YAG laser with 400 mJ/cm2 laser energy’s has been used to ablated pure Indium target and deposited on glass substrates . The resulted films show High transparency reached to about (85) % which found to decrease sharply with the substrate temperatures. The estimated optical band gap found to be about 3.6eV at optimum substrate temperatures (70 Co). The FTIR results insure the formation ofIn-O vibrational bond with different vibrational intensity depending on substrate temperatures.